Windows 7 is also the fastest selling OS ever, it's been out long enough for it to have established a good rep.
I see what you mean about their rep, but we need to let go of it. Office 2010, Win7, the 360 + Kinect; Microsoft is in very different league now compared with them 5 years ago.
I also finding the average user have significantly less issues with Win7 (no actual crashes, just usability issues of the technologically impaired).
I deal with plenty of Mac users daily, while most of them hardly ever complain or mention issues, I do encounter them. Like I said, the scale is much, much smaller comparing PC to Mac.
I guess my experience with them isn't positive though (limited as it is) - we bought a couple Macbook Pro's at work about 2 months back just for Keynote shows and I got the spinning ball of death to hang the machine twice within a week. And I was just doing some basica Keynote presentations.
The OSX interface sucks - you can't customise anything on it, and it just feel completely unintuitive.
Haters gonna hate, as they say.