Windows has *always* needed upgrades and new versions. Most IT people know this. Most people here know this. Most of the ire is targetted at what Microsoft got wrong in the upgrade process. UAC is one example.
We all know what UAC is for - but the concept has been around for a very long time in the Unix/Linux world. It's called 'sudo' and it generally works very well. Microsoft had two problems to overcome with UAC: they can't resist trying to re-invent computer security methodology, and their Windows architecture doesn't lend itself well to doing it properly, anyway. And I guess the latter leads to the former, really, too. :-)
We know there are always the usual round of derisions about a new Windows release. However, the end-user response to Vista has been less than with XP and that was less than with Windows 95. Plus Microsoft has either gotten more aggressive in getting people to upgrade, or it's more visible. Sure, the industry has changed since XP and much more since Windows 95.