Just not interested
I don't use Vista or 7 for the same reason. I just plain don't need them. XP does everything I need it to do, and there are TONS of modifications you can do to it to make it work the way you want, such as have it look like Windows 2000, the most stable release yet, which still is in use, as well, and had features taken out by XP. I still run a Windows 2000 unit which works just fine.
There is NO reason to have a new Windows OS on anything but one forced down your throat because you bought new hardware.
What's more, there is a great alternative FOR free out there, which you can customize to your hearts content, easily. Pick your flavor of Linux, if you have old hardware running Windows 98 to XP and want it to be faster, better, and more useful.
To recap, sure, you're going to buy a new Windows computer in 2013 that has 8 on it. I guarantee you'll have problems adapting if you're anything like me, and you'll want to just trash it. I throw up my hands in despair every time I have to use my wifes Windows 7 laptop, with Office 2010. Silly little "preview windows" which I can't tell apart on the taskbar, nothing is installed in its proper place, horrible screen resolution (that she won't change to make it more readable) AND crashes every time an update is issued. No thanks.