They disliked Vista because they think that XP is better, because they're more used to it. They were working on an OS that was nearly 5-6 years old, and didn't want change. Most of them hated it over User Account Control, because it would "get in the way of things", even though you could easily disable it, but apparantly people were too thick-headed at the time to realize you could.
I mean, look at today still. Windows 7 is out, and yet most professionals aren't using it. They're still using XP, an OS that's 10 years old now.
I've been using Vista almost ever since it came out (sans the year or so I used Windows 7 beta), and rely on it. I can't rely on Windows 7 on a laptop I paid well over $1000 for, though.
I'm sorry what you say, but I will never believe Windows 7 is more stable than Windows Vista. There's no performance gain or loss on both OSes (yes I've checked on the same machine), but Vista has been ultimately better for me.