We have no idea how many thousands of people Microsoft had to go through in order to elicit these few positive responses.
I work in IT and Vista is just a major headache. It's fine once you get used to it and turn off all the flashy features, but at that point it's hard to see the difference between it and XP. There are a lot of changes for the sake of change, and many of them hurt usability a lot. For example, the old Network Connections control panel has been changed and hidden multiple mouse-clicks deep for no real reason. What if I want to enable a network adapter? There's no easy way to do it!
Maybe the next version of Windows will bring real changes that make sense, rather than slapping a pretty face on an old OS and changing things around just enough so people don't notice it's the same thing.