A better question is why they felt the need to dump XP. That was one amazing OS. Couldn't they just fix the issues and release an XP2? Bastards!
They did, they called them Service Pack 1, Service Pack 2 and, unimaginatively, Service Pack 3. But there's only so far you can go with a service pack and updates before you have to give up and move on. XP Service Pack 2 was a good operating system, but the world is not the same place it was in 2001. The internet has taken over computing in a way that was still being imagined back when XP was being designed, it's one of the reasons why XP was horribly insecure. Hardware is much more advanced now, we've moved on to 64 bit dual/quad processors and XP is not optimised to run on those systems. The attempt to make a 64 bit version of XP was buggy and unreliable.
Computer and electronic technology advances at a rapid pace and it is absurd to suggest that we should use software designed to run on hardware from eight years ago, almost a completely different age from the one we're in now. XP had a good run, it was Microsoft's primary OS for twice as long as it was supposed to be, but we can't stick with it indefinitely, that would only encourage technological stagnation.
I disagree with that. The Start menu is supposed to be an abstraction for of all those messy application files, and very little more (logoff/shutdown, and there's an argument for those not really belonging on a "Start" menu!).
See, I would disagree with that. The Start menu by its very name indicates that it should be the one-stop-shop for everything you need to do on the computer, be it opening a program or searching for your files. Now that computers are used as media hubs as much as they are about computing it makes sense that the Start Menu would evolve to reflect that.
Bolting on yet more needless disfunctionality is what's kept causing Microsoft software's problems over the years...
Then turn it off. Control Panel, Programs and Features, Turn Windows features on and off, untick Windows Search and press OK. But I'd suggest you give it a try first so that you can see it is a big time-saver.
If they're demoting applications to "just another file", then they need a sane way of bundling and managing an application's related files into one bundle (like well-behaved applications on Mac OS X).
They're not demoting anything, Windows doesn't know what you're searching for unless you tell it so Star Search brings you an organised list of everything it finds. If you want to specifically search for programs then open a dedicated search Window and do it from there.
If I want to search my computer, then I'll search from My Computer. There's no reason I should be waiting for several seconds for irrelevant search results when I would've already had my program open from an XP-style Start menu.
But it doesn't take a few seconds, it is near-instantaneous, updating with each letter. It is much faster to type "brot" and see Brothers in Arms than it would be to open my music folder, open the Dire Straits folder and then look for the song.