An oft asked and never fully answered question, but although I'd rather think it's just paranoia on our part, I'm inclined to agree with you.
Of course, many of us Mac users hate PCs as well, although in my personal experience in most cases it's with good reason. I, for example, spend a significant portion of my workday troubleshooting PCs, so I feel like if I hate Windows, I have ample reason and experience to back up that belief. There are a lot of irrational knee-jerk reactions from Mac users, but I still argue that many, if not most, Windows-hating Mac users spend a significant amount of time using it at work or before they switched, giving their opinion something of a logical foundation.
PC people seem to be touchier for some reason. Those with little computer experience at all, those who fancy themselves power users, and some of those who actually are pros--a lot of people, almost all of which have never used one, just can't seem to stand the thought of a Mac.
I'd have to say that experienced pros who are aware of current Mac developments, even if they're not actual users, seem the least likely to irrationally hate Macs, which would make sense because they can see the benefits of the MacOS, and are familiar with the weaknesses of Windows.
Anyway, I'm just sort of rambling, but I'd be interested to hear if anybody has any real insight into why so many PC people who've never even touched a Mac seem to cringe at the very thought of one.
My best guess is that a lot of people are frustrated with their computing experience, and it would make them feel even worse if there was a better alternative out there, meaning they've been tearing their hair out for nothing. Whether Macs are actually that much easier to deal with or not isn't important. What is is that Mac users generally seem a content bunch who like using their computers, and that'd be annoying to me, too, if I hated mine or routinely got frustrated using it.
Misery loves company, I guess. Either that, or they just don't like the thought of anything different.