See, Apple is like Notre Dame. If you went to Notre Dame, you're a Domer: all hard-core ND-green-and-gold-running-through-your-veins. If you didn't go to there, you don't particularly care for the school and you fucking hate the ND fanatics.
The same is true for Apple. If you own an Apple product (minus the iPod - that's a whole different argument), you're an Apple Geek: white-and-grey-coursing-through-your-veins want-to-have-Steve-Jobs'-babies/job/power/money. If you don't own an Apple product, you don't particularly care for the products and you fucking hate the fanboys.
Amazingly enough it is possible to own an Apple product and have a clue (i.e. not be a platform bigot). Most technical Mac users that actually have a clue tend to use all three major platforms to some degree, and have a laundry list of problems with both Apple and the MacOS (
FTFF stands for "fix the fucking finder", an acronym that no longer needs explaining on Mac forums, much to my annoyance"). Basically, the fanatics give the rest of us a bad name. See
http://funroll-loops.org/ for the Linux example of the same type, and this thread (or basically any other tech forum thread that Apple is mentioned in) for the Windows example.
That said, one of the reasons why the Apple fanboys tend to be so defensive is that attitude others have towards them. I have been punched, insulted, ignored, yelled at, discriminated against, and scorned for using a Mac. I've had the head of the CS dept. at a local college tell me to "get a real computer". In my case this has just led to a generalized hatred of platform bigots, but it's remarkably easy for it to turn into retaliatory bigotry.
In summary: I'll use whatever fucking computer I want to, and you can use whatever fucking computer you want to, and if you try to mock me for my choice you had damn well better have at least some knowledge of all three major operating systems, cpu and system architecture, programming, and UI design, because otherwise you're going to come off as looking really silly.
Summary of the summary:
All computers suck.. I happen to prefer the way mine sucks.
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<edit> Just to be clear here, this was targeted at several people, not just mberan's post (which seemed mostly reasonable aside from the stereotyping). </edit>