Everyone I knew was against UAC popups, including security professionals.
They were likened to California Prop 65 warnings: so prolific as to be ignored, and arguably causing more harm than good, because just as apparently since EVERYTHING causes cancer one can't make decisions about avoiding things that actually do, so to does EVERYTHING trigger a UAC popup and so who gives a fuck, one more thing to quickly ignore and click through.
UAC is the correct idea (elevated user privilege levels), but implemented in the worst way possible. As I understand it, things have gotten MUCH less annoying since Vista, but it still left a bad taste in people's mouths.
It pops up with exactly as much frequency as a normal user account in most Posix-like systems would require "su" of one form or another. For exactly the same reasons. It's just expected behavior for those systems, but completely unacceptable for Windows.
And we wonder why Microsoft sucks so bad at securing Windows.
It was the collision of Microsoft trying to limit "run as admin" and Windows developers taking users running as admin for granted for too long. There had to be a period of pain as "if it ain't broken don't fix it" developers got around to not asking for unnecessary permissions.
These days you mostly see the prompt when you're installing or updating an app, which makes a lot of sense.
What I mean is, this is Microsoft's fault so far as users got in the habit of running in admin in the first place, but I doubt you would've been able to do better given where Microsoft was with its software ecosystem going into Vista.
They were likened to California Prop 65 warnings: so prolific as to be ignored, and arguably causing more harm than good, because just as apparently since EVERYTHING causes cancer one can't make decisions about avoiding things that actually do, so to does EVERYTHING trigger a UAC popup and so who gives a fuck, one more thing to quickly ignore and click through.