The reality is that those things are actually becoming less important for the consumer market. I hate to be of the '8GB should be enough for anybody' ilk, but for the kind of things that people are actually doing, that's probably true.
Think of it this way: the Macbook is the laptop you should be recommending to MOST people that ask you for advice. You only deviate from that advice if they have some sort of restriction or requirement. There are times where you might want to recommend the air, and for nerds you should recommend the pro. But the stock Macbook is going to be my recommendation every time without any extra info.
Similarly, if you need something with upgradable RAM, you're simply not the market for a Mac Mini anymore. I had my Mom buy a new Mini last year when her old one kicked it. She will never need to upgrade the RAM. For the things she does (playing MP3s, watching YouTube, email) the machine is vastly overpowered for her needs. That they make it in very few configurations is less of an issue because it's reached appliance status. You may as well complain that your fridge doesn't come with an upgradable cooling unit and spare bays for future extensions. It's just not that sort of tool when you're talking to most people.
For my part, I'm still on an early 2009 iMac with a 2013 Mac Mini that runs headless. 8GB of RAM really IS enough for 100% of what we do at home. I'd only want more RAM because it's one of those things that it's always nice to have more of just so you don't have to care about what's running, but it's not really necessary. I'm already running a lot more things than I need to.