Design over usability, by design.
Microsoft Store Salesperson: You'd like this Sony
Vaio notebook, sir?
Computer Buyer: Yes. Core i5, 8 gigs of RAM, sounds really nice.
Salesperson: It also come with Windows 8. On Windows 8 you'll have access to hundreds of new "apps". It's really great.
Buyer: Oh, I don't want that. I just want to use iTunes
Salesperson: You can do that on Windows 8, sir. Just click on the "Desktop" icon.
Buyer: *playing around with the store model* Oh, okay, well.... wa... where is the Start Menu?
Salesperson: It was replaced with the new Start Screen. There you have access to all of your applications, just like the old Start Menu.
Buyer: Alright, well, how do I go to the Control Panel?
Salesperson: It's really easy. All you do is right-click the desktop and choose Screen Resolution, and then just click a few other categories and you'll find it. To change the Start Screen applications and personalization you just use its own control panel in the Start Screen.
Buyer: ...Is this notebook compatible with Windows XP
Salesperson: (mentally) *FFFFUUUUUUUU