I have to disagree here. Apple produces computers that people can use without being a computer geek. Open source, while having a sort of 'nerd hip cool' to it, just isn't that useful to the vast majority of people. You know, the people who just want to use the damn thing. Not spend hours fussing with it to get something done.
I have Ubuntu on one of my machines, Windows 7 and OS X on a couple more. The Ubuntu machine is fun, but when I am in a hurry and need to get work done it is my last choice. By trying to cram 'Geek Heaven' software and OS on people you are locking out a huge segment of society from a useful and valuable tool.
The people for whom Linux et al is useful already have it. People have voted with their wallet, and have chosen to pay for something that works and is useful instead of the free option that really isn't as good.