Wow, so much vitrol, so much lack of understanding.
It's okay to be ignorant. Lots of devs are, even ones that have been in the industry for a good long while.
1) Contracting companies make money off you
Yes, but that's just sour grapes - if you accepted the contract at the rates and benefits given, then, you accepted it.
2) They're charging x% more than you're making! You should be making that much
You sound like someone who's never done independent contracting before. First, how are you going to get in the door to bid yourself out for these contracts? Are you going to go through their agency vetting? Provide your own worker's insurance (ensures your contract will be completed if you're unable to)? Provide a history that shows more than a single competent individual with a single set of skills? Don't forget providing your own medical insurance. I've had to do this before for myself; for a job that I'd normally peg in the 80$/hr range, in order for me to be profitable, it'd need to be in the 200-300$/hr range. and see item 3 below ...
3) You weren't going to get that job by yourself anyway.
When it comes to devs, it's rarely a choice between contract or perm for the same position. It's one or the other.
First, perm employees are - to the company - almost always more expensive than contractors, even given an invisible markup that goes to the contracting company. The cost of onboarding is high, benefits are high, it's all very expensive, more so than the contract cost.
Next, contractors are easier to get rid of, just cancel the contract - so if you don't work out, it's painless to excise you. It's much harder to get rid of employees. There's unemployment, there's a higher potential for lawsuits, there's morale problems, etc.
Additionally, many big companies use contractors as budget stuffing. You might not know this if you're outside of management, but in many places, coming in under budget is bad - it means your next year's budget will be reduced. One way to avoid this is to use your discretionary budget to hire contractors. They're effectively uncashed checks - you can cash them any time you need to, or just wait out the year and let them soak the remaining budget.
A counterpoint to the above issue, many small companies use contractors because they cannot afford to compete in the HR/recruitment space on their own. Many shops specialize in software design, and they don't have a separate department to vet and sort thousands of applications, much less maintain social presence on career sites and such required to snag good employees. They rely on contract agencies and rarely even post their positions publicly. Most contract companies even give discounts when you mark them as a sole provider, so it's the best way to get good candidates without spending your lead engineer's time.
Last, since these budgets are almost always separate from a fixed budget to be used purely for headcount, it can be used to hire additional personnel when you're not allowed to otherwise.
All in all though, it means most of the jobs going to contractors are not ~ever~ going to perm employees, and vice versa.
4) Recruiter cares if you sent them a nice email?
Yes, they do. Their livelihood depends on placing candidates. For them, it's mostly statistics; throw enough candidates at a job, a certain % will stick. How do they hedge their bets? They find _good_ candidates, and they keep in touch with them. Some of that is social - just a willingness to communicate with them is a better risk than someone who never responds. It pays for them - literally - to keep in touch, to maintain that relationship. So they make special notes of the nice ones, of the successful ones, the ones that interact with them, that agree to go to lunch with them - of the ones that can help them bring in a payday. Especially in that environment, they're very used to monetary incentives, and so it's not rare to have them bend rules or make adjustments and slide you a little bit, effectively paying for your future interest or present help.
5) Contract workers with corba/vacation/etc
Yes, contracts can come with benefits. I've worked for one that had no vacation time, and a meager health insurance policy. I've worked for another where I asked for and received 3 weeks paid vacation, full benefits including stock purchase and a 401k. Have you never heard of negotiation?
Oh, a side note - guess what sort of person they're more likely to negotiate with - someone who never responded to emails and came in just to sign the bottom line, or someone who's sent them a dozen candidates, who's met with them on a few occasions and acted like a genuine person, who congratulates them on their promotions and important life events like marriage or kids? Someone, in a nutshell, that they might like, and who it pays for them to keep happy?
6) In house recruiters
Lots of larger companies have in house recruiters. They seek ~you~ out. If you haven't been contacted, well ... there's probably a reason for that.
Amazon, to name one, has been very active in this scope lately, and a surprise to me, they're almost always personalized letters by individual department management - which shows a pretty high level of respect and involvement in the hiring process, and I wouldn't be surprised to learn that their employees end up being slightly higher quality in turn. As much as we like to bash it, Microsoft is also active in this way. ...
Aside from all that, I've never been a recruiter; I've been doing software development with the occasional side of sysadmin (in jobs where many hats were worn) for about the last 20 years. I'd never want to be a recruiter. For 100k, I'd not only prove it, I'd sign documents. I'm just not so foolish as to dismiss a potentially lucrative business contact with really no downsides.