There's a whole lot of them. Almost every ethical theory seriously entertained by contemporary philosophers (many if not most of which theories support some concept of rights) is something other than divine command theory ("from God") or ethical subjectivism ("people just made it up").
I don't know what you're referring to so I'm going to go with "no", but I also get the feeling that you completely missed my point.
Does logic come from God or is it just something people made up?
Does mathematics come from God or is it just something people made up?
Does reality come from God or is it just something people made up?
Does morality come from God or is it just something people made up?
False dichotomies, all of that. (And not even a dichotomy at that, because "coming from God" means someone -- God -- made it up. "Nobody made it up, it just is" isn't an option?)
Might I suggest The Database Engineering Perspective on Gay Marriage, which humorously explores the formal, structural similarities and differences between different kinds of marriage (straight, gay, poly, intransitive... asymmetrical? reflexive? etc) in a milieu that readers of this site should appreciate.
"Rights come from God" and "rights are just made up by people" are not the only two options.
California may be "generally considered more liberal" abroad but it's really only liberal in federal elections. State elections tend to swing pretty conservatively. And broken down county-by-county, it's a shockingly perfect microcosm of the US as a whole: liberal on the coasts except for the south coast, and conservative inland except around the big lake on the border.
Here's a fuller illustration of that toy model of a market to more completely illustrate how the existence of rent breaks it.
This market consists of two identical people, one kind of consumable good (food), one kind of capital (land), and one kind of labor (working the land to produce food). There is exactly enough land to produce enough food for normal consumption for two people. The two people agree on what the rules of acceptable behavior (laws) and division of property are, so we don't need to worry about external law enforcement here. We will explore a couple of different scenarios of different laws and different divisions of property.
If the land ownership was evenly divided, the normal state of affairs would be for each person to work his land to produce food for his own consumption. Trade between the two people could be possible still -- one could give the other some of his food in exchange for the other taking over some of his labor, or they could divide the labor up into different types (planting, watering, harvesting, etc) and each do that for the other in exchange for some quantity of food -- and if the law includes laws against violence, then neither can coerce the other and all their trade would be free. Sounds wonderful.
But now, say one of the people (Alice) only owns 1/4 of the total land, while the other (Bob) owns 3/4 of it. Alice now cannot produce enough food for her own normal consumption, whereas Bob could produce an excess. Of course that means Alice is also working half as much as she would, and Bob is working one and a half times as much, so maybe that seems fair, but there are now pressures at work that will quickly make it unfair. Alice isn't eating enough, and Bob has more land than he really need to provide for his consumption, so Bob offers Alice a deal: "I'll let you borrow my extra land to work, in exchange for just half of its normal yield." So Alice gets some more food, and Bob gets more food too so he has to work less, and they both win right? So this is an obvious no brainer for both of them, a totally voluntary, free market transaction, right? Everything's great?
Except that now Alice is working a normal full work load but only getting 75% of a full crop from it, and Bob is getting a full crop but only working 75% as much for it. And this will continue indefinitely, and never end. Just because Bob started out with more than Alice, Alice is now stuck permanently getting less for her work than Bob, and Bob can permanently live a life of leisure on the back of Alice. Not because one of them did anything to win this position, not because one of them is better than the other, because remember we stipulated that they are identical; it's just because one of them began with more capital than the other.
But wait, it gets worse! Alice is still not eating enough, and desperate for anything that she can to get more. And now that Bob only has to work 75% of his land to meet his own consumption, he's got another quarter-field now lying around that he could lend out to Alice as well... in exchange for part of its normal yield again, of course. Which means Alice is now working even more than a normal full load and still not getting a full crop, and Bob can work even less and still get a full crop. Which means Bob now has another portion of his field he's not working anymore, and Alice still isn't eating enough, so she'll gladly work that too, in exchange for a part of it's yield sure, she needs the food so it's better than not. The endgame of this progression is that Alice has to work both fields in full if she wants to get a full crop to herself, meaning Bob doesn't have to work at all, still gets a full crop to himself, and Alice is his slave.
(Worse still, if Bob was really smart and Alice was desperate enough to fall for it, Bob could keep working full time, trade the excess he gets from Alice back to her in exchange for her land -- bought, not borrowed -- and gradually own even more and more of the land and make the whole scenario above worse and worse. Bob's ability to leverage his capital advantage to produce an excess of product allows him to increase that capital advantage further and further and accelerate the whole process -- at the accelerating expense of Alice).
Now, consider if the law was that you couldn't create those kinds of borrow-at-interest obligations, i.e. you couldn't rent. That's not to say that Bob couldn't let Alice use his land, or that Alice couldn't give Bob some of her crops; just that Bob couldn't oblige Alice to give her crops in exchange for use of his land. Well, you might say, that's just going to mean Bob won't let her borrow the land, and Alice will be permanently starving, and half a field will lie fallow since Bob doesn't need it. But wait! Isn't there an obvious, free-market solution to both of those problems, that benefits both of the parties? Bob could sell his extra land to Alice! Alice gets the land, and in exchange owes Bob some large amount of food (so Bob doesn't have to work as much to grow his own). Of course she'll have to pay that over time because she doesn't have enough to feed herself as-is. And of course even with the land, Alice will only be able to produce enough food to feed herself, so she will need to get more food to give Bob from somewhere else... meaning, from Bob, which she will have to trade her labor for, giving Bob even more leisure at no loss of consumption.
So for a while, you get something that looks just like the terrible outcome of the second scenario above. Alice works more than a full load just to keep a full crop at the end of the year, and Bob gets to slack off and still get a full crop to himself. But unlike the scenario above, this is temporary; with every year that Alice is working extra to pay off the land she bought from Bob, Alice gets more and more equity in the land, and Bob gets less and less. And eventually, Alice owns a full field to herself, and Bob only has a normal field with no excess. And Alice can stop working extra to pay off Bob, and Bob has to start working a full load if he wants to keep his full crop. And then we're back at the free, fair, and equitable arrangement from the first scenario. We have gone from a capital inequality to capital equality, redistributed wealth from the rich to the poor, all through completely voluntary transactions, with no coercion!
And all we had to do for that to happen was to agree that one person can't be obliged to give someone something in exchange for merely being allowed to use something else. Exchanges have to be proper trades; if someone is going to owe you something, like Alice owed Bob food, then you have to owe someone back, like Bob owed Alice land. Just do that, and the natural mechanisms of the free market will automatically move capital from the rich to the poor and bring everyone back to equality. But allow rent like that, and the free market breaks completely, wealth concentrates, and pretty soon the poor are slaves to the rich, and everyone turns the other way because every step of it was "voluntary", including the rental contracts.
But we don't allow people to "voluntarily" sell themselves directly into slavery -- such contracts are invalid -- so why would we allow contracts that indirectly tend toward the same result, when we could just consider them invalid and then let the market sort itself out?
You can do whatever you want with your property (so long as it's not harming someone else or their property).
What you can't (shouldn't be able to) do is create contractual obligations whereby people owe you money (or anything) in exchange for you allowing them to do things to your property.
Which means if you want to profit from your excess, you have to sell it. You don't get to get paid for something and also keep the thing. You want money for something? You lose the thing in return.
Your machine is apparently magic as it requires no input whatsoever on your part.
There are simple arrangements of sales that emulate rent in that capacity (a "rental shop" would sell above market price on long installment terms, and buy back below market price in one lump sum). The same kind of arrangement would also be fine for land, and would serve the functions where people actually want "rental" housing, while automatically becoming more like a sale for people who really just wanted a sale in the first place (or who just find themselves renting for so long that they might as well have just bought one... and it turns out, they technically did, and eventually it's paid of and done).
And then when it expires, all the places they would have turned to rent instead are now owned by rich Americans and priced out of their range, the bulk of the country (the poor, the renters) are forced to move. Their landlords are happy with the whole deal of course, that's why they sold, but the majority of the populace are fucked. That they may be a slight delay in their fuckedness is immaterial.
The people who were forced to move were not the same people who chose to sell. A small portion of the natives owned the land and rented it out to the rest, as is what usually happens everywhere. That small portion decided to cash out and sell their land to the rich Americans, and walked away laughing, while all their tenants suddenly can't afford to live in their homeland anymore.
The reason this problem exists is rent. Without it, there would be no problem, nobody could be forced out of anywhere, and if they left it would be their choice and they would profit from it.
Yes, it is exactly like feudal Europe. I'm glad you came to that conclusion by the end of your post because I was just about to make it clear for you.
And yes, feudal Europe came into existence because of runaway "capitalism" (not under that name), and worse, outright theft. Not because of free markets though, because the forces that allow a market to collapse like that make the market not free.
In a the worst kind of unfree market, people will just force other people to serve them at gun- or swordpoint, and that's slavery. The powerful, the slave-owners, will of course collude to assist each other in keeping their slaves, and since they, being the powerful, will constitute the government of their society, that collusion to keep the slaves enslaved will amount to the force of law.
In a slightly freer market, where somehow enough people with enough collective power have agreed to disallow such violent coercion, slavery like that isn't quite allowed, but some people are still allowed to own all of the resources and "defend" them against unauthorized use at gun- or sword-point, and everyone who's not a part of that owning-everything club must pay their feudal lords or else be forced off the land... onto someone else's land where they face the same deal.
In a slightly freer market still, the kind we have today, people have a bunch of different work options besides just farming someone's land, and the distribution of capital is slightly more widespread and more diverse than just land, but most people still have to work upon the capital owned by a small percentage of the population, and live on the land owned by a similarly small percentage of the population, and the fact that they get to work one lord's "land" and then live on another lord's land doesn't change the fact that they're still paying a big chunk of the product of their labor to both those lords for the privilege, and they have no other option because everything is owned by someone and you can't even just go live in a tent in a field somewhere and garden for food without paying someone else for the privilege of doing so.
In a truly free market, everyone would own their own homes and businesses (or own each others' businesses, because stock investing is a good idea; and work each others' businesses, because division of labor is a good idea too), and just owning something wouldn't be a mechanism by which to generate income from those who own less. The rich would enjoy leisure only at the cost of losing their riches, and the poor who worked to provide for that leisure would accumulate riches in the process, creating a natural and voluntary redistribution of wealth from the rich to the poor, in the absence of a mechanism like rent that then takes the riches paid to the poor and gives them right back to the rich to pay the poor with over and over again, allowing the rich to live at leisure indefinitely, on the backs of the poor.
So yes, runaway capitalism leads right back to feudalism, just like runaway feudalism leads right back to slavery. Rent (including interest) is the defining feature of capitalism, and the last modern vestige of feudalism, and if we want a truly free market that's not going to slide constantly back toward feudalism and slavery, we need to be rid of it.
The rich are the goddamn parasites, and rent is the exact fucking mechanism by which they parasitize. A gigantic portion of the income of the poor goes to paying the rich for the privilege of living on their borrowed capital, which the rich then use to acquire more capital and bilk the poor even more.
And what the fuck do you mean the poor have the same opportunities... are you a blind fucking idiot? How the fuck is the child of a crack whore and a dead gangbanger going to get the same opportunities as a trustafarian growing up in Martha's Vineyard?
The original homeowner doesn't get to force the buyer to sell it back a month later; and the buyer can choose to sell it to someone else instead, if he can find a better deal elsewhere. But if a bunch of different people all want the original homeowner's place for a month at a time and don't want to bother looking for someone else to buy, and is willing to accept that $1500 loss for the convenience of a temporary place to stay, then sure, they can do that, and you've got something that looks just like rent.
On the other hand someone who just wants to stay there permanently can keep paying those $1500/mo payments and 16-ish years later they will own a house, which is what you should fucking expect if you spent $300,000 on housing, but what doesn't happen today because people get stuck renting instead, and then decades later have paid way more than a house would cost and yet have no house to their name.
Yeah, that was all supposed to be an analogy for things like that happening on a smaller scale domestically; it just seemed like the injustice of it would seem more poignant if we were talking about rich Americans pushing poor foreigners out of their homes, rather than just Americans and other Americans.