That's kind of the reason I wouldn't buy a mac. I like OSX from a design perspective (read: it looks pretty), but have no reason to switch over completely (re: lose the ability to customize my pc as much as I want from a hardware perspective). Maybe if I had as much of a problem with windows as a lot of the people preaching macs do I would, but I don't. In fact, I have virtually no problems (except from ati...which would be easily fixable if I wasn't more lazy then I am annoyed).
I'm not saying one is better then the other, because I don't think it works that way really. Both have their strengths (as does linux). Boot Camp and Parallels also defnitly ads another benefit to macs (it's a lot easier getting windows up and running on a mac then getting osx up and running on a pc) but I'm still not willing to make the switch, mainly for hardware reasons, but also becuase there is virtually no need for me. The one exception I could think of would be for a laptop. The thing with that is I a.) don't need that much power in a laptop to justify spending that much money on it (I mean, why not just get a better gaming desktop for cheaper?) and b.) For the same price I could get a comparable tablet pc, and I don't care what anyone says, those things are fucking cool.
But again that's just me and everyone has different priorities when it comes to computers. The thing that probably scares a lot of people away from macs is that most people who try to sell you on them are total morons.