Apple's only real success with the iPad (in terms of a device) is to make an OS that wasn't useless with a touch screen. Of course they made a lot of compromises with that and sold it primary to "consume" content (though it's since moved away from that). Otherwise iOS is a frustrating piece of shit, and Android isn't much better.
MS are competing with Apple in that they're trying to capture the tablet market and integrate their own ecosystem. As part of that they're trying to unify the platforms, which isn't a bad goal. I don't know why it's such a bad thing to have my desktop and tablet share the same ecosystem. What Microsoft screwed up was enforcing tablet gestures onto desktop users with mice. That part is bullshit and that seems to be where all the complaints come from. I think another issue that people have with the change is that we've had the Start menu since Windows 95 and it's only really changed with an added Search bar over the years. The Start menu needed an overhaul or a replacement, and we got it. I think the icons are still too large for a desktop but functionally it's not a massive change. Really I think a lot of the resistance to the Start screen comes about from a sense of tradition than it being an actual UI nightmare (except for the gestures, again that's bullshit).
The other major "complaint" (fear-mongering might be a better term) about trying to lock x86 apps is absurd. They won't do it. They'd be stupid to try it in this day and age. It'd kill the golden goose. Again the software library is absolutely massive and legacy support is still remarkably extensive (yes, CPUs etc, lease don't bring up your P4 again I already know the story). Do you honestly believe they'd kill that and infuriate pretty much all of the business users relying on that support, along with pretty much everyone else using Windows?
10 or 20 years from now things might be different, but computing will probably be a hell of a lot different too (if you tried telling us 8 years ago that we'd all be buying games on Steam and you'd have been laughed out of a forum) so it might not be so much of an issue. Whether or not the Windows Store is any good remains to be seen (and part of that will be up to the developers - plenty of them can't even manage to release proper Android apps and just target iOS). But again, the x86 lockdown is pure FUD. Croteam are picking up someone else's ball and running with it. GabeN is worried about one thing - Steam's Profits, and you can bet that he'd love an OS that was locked into Steam's walled garden. Unfortunately, most of the people on RPS would line up to buy into it.