I've been a happy user of Apple products since the '80s, so I have more than enough experience with people who don't like Apple products, which in the modern day has extended to not liking the company itself, and its customers (there are a lot of them, too), and maybe not liking the people who work for it, or the guy who founded it.
I suspect it comes from a strongly-held personal dislike of Apple products or corporate style for one reason or another, an opinion that has been getting clubbed over the head with real-world success and popularity for quite a few years at this point, making people kind of bitter--that happens when how you think the world should work and how it does don't line up.
Personally, I've used enough technology in the past 30-odd years to be able to tell the difference between genuine preference and irrational idealism. And I mean that in both directions. But, hey, this is the internet--irrational idealism is what discussion forums are made of.
Likewise, I have enough of an understanding of human nature and the creative process to understand the difference between success, humanity, and personality, as well as the fact that humans are not static, unchanging creatures who can be defined by their actions or beliefs at a single point in their lives. So it's also fine to have differing opinions of someone based on their humanity, versus their contributions to society, versus their personality, or to weigh things differently within those categories. I think looking at a person as a balanced sum of these various things is most interesting, but hey, this is the internet--being judgmental (positively or negatively) is what discussion forums are made of.
But here's what bothers me: I can no longer tell the difference in discussion forums between people who are playing an exaggerated, irrational caricature of an Apple-hater to troll, and actual Apple-haters. I likewise am having more and more trouble telling whether some of the more extreme Apple fans are really that extreme in their beliefs, or are just someone playing an exaggerated Apple fanboy either to point out how ridiculous they think fanboys are, or to troll people who dislike Apple.
I really can't tell the difference between extremists and trolls anymore. I keep assuming that someone who is expressing a ridiculously overboard or transparently, factually wrong position must be just playing a character, but I really have to wonder.
I have this suspicion that eventually some technology forums will be composed entirely of anti- and pro-Apple trolls getting into flamewars with each other, thinking they're "winning" the lulz contest all the while.