I don't get the whole "anti" thing

I know that Apple fanatics can get a bit wearing. I also get that if you don't appreciate the "added" value of what Macs and iPods offer, you won't buy one. Similarly, if you don't get why people buy porsches - stick with the mustang. But where does the anti apple thing come from? I have been reading a lot iPhone reviews today and I see a lot of self proclaimed "anti-apple" people commenting. Why be anti anything? I think this is mental poison. We should all find more issues to advocate - am I anti-anti?