The problem with people claiming that it will be just as simple as it is now, and you can just upgrade as often as you feel like, and only upgrade every 5-6 years if you want to, and you don't have to mess with settings if you don't want to, is that no, of course it fucking won't be as simple as it is now. Microsoft might make an effort to make it simple, and they will sure as hell try to convince you it's simple, but it won't be anywhere near as simple. Sure, theoretically your box will be forwards-compatible for five years and will just work for you. But in practice, it's gonna look a hell of a lot more like this:
Hey, you want that game in that series you love, but guess what? The developer decided to make it only two generations backwards-compatible instead of three, because they didn't want to put in the effort to optimize it for your model. So you're shit out of luck. How about that other game? Oh, damn, its performance is good on other models, but shitty on your model. Shoot. At least you always remember to obsessively check Digital Foundry before every purchase, a thing you need to do now that performance and developer effort can vary wildly between models!
Well, how about this third game? You'd better look up its performance too. Looks good! No wait, shit. It only gets a stable framerate on the special edition of your model. You know, the one with the overclocked GPU, the one that came out 6 months later with that FIFA game bundled in. Yeah, that one.
Maybe you should look into upgrading your machine's hardware? Some of these machines can be upgraded; you know that. But you're just an average-Joe consumer, and you don't even really know what phrases like "CPU" and "RAM" mean. But you do the annoying research to figure it all out. But alas, the specific hardware upgrade you wanted isn't available for your model. No, wait; they used to have it, but it was discontinued last month. Now it's really expensive on eBay. Shit!
Perhaps you could tweak the settings. But you hate messing with settings. You don't want to game on a PC. That's why you bought a console. Microsoft promised it would just work. You sigh.
You're feeling a little frustrated when your programmer friend happens to call you up. He's been making an indie game and it's been going well. But shit, he's getting really nervous about optimizing and testing his game on a half a dozen different Xbox models. He's really thinking of just releasing the game on Playstation. Shoot, you were really looking forward to trying his game.
Maybe you should consider just buying a newer model? But they're so expensive now that Microsoft releases so many of them, each needing its own round of R&D and stress testing and everything else that goes into designing and manufacturing hardware. You miss the days where developers could afford to take a loss on hardware, since they only had to sink those hardware design costs every 6 years or so.
You think about it. And then it hits you. Just buy a fucking Playstation. Because there's only one of those on the market, and it actually does just work.