I can't speak for life-long Windows users, since I've been primarily a Mac user since 1984 (and even used Apple computers exclusively before the Mac)
But, I think Windows 8 was a necessary and logical evolution. It seems far more natural and intuitive then the old Start button with a million nested folders theme to me.
I used Windows XP for a while and found it ugly and kludgy, Windows 7 is the first version of Windows I actually like and enjoy using. Windows 8, I think will be even better. People cannot expect Windows to sit still for decades the way it has in the past.
Microsoft had to do something here and the Win 8 interface was a logical choice IMO because:
1. Microsoft knows for a fact that tablets are eating away at PC sales.
2. Microsoft needs to get a foothold in the increasingly important smartphone market.
3. What better way to ensure future dominance of the Windows platform than to tie all three together, both thematically and with seamless software interoperability.
I think people who don't see that are missing the point. No one is going to stop you from clinging to Windows 7 for the next 10 years like many did with Windows XP, so go right ahead, but Microsoft has to continue to evolve and I, for one, applaud the "new" Microsoft that is making attractive and intuitive user interfaces for the first time in it's history. I am one die hard Apple customer who they never would have gotten any business from if they hadn't. My next computer might even be a Win 8 PC instead of a Mac.