Well that and the fact that Apple made a better Unix desktop.
I would not for one minute argue that Apple made a desktop that a lot of people like as an alternative to Windows. But you're actually arguing against the whole design ethos of OS X in that's it's designed to be simple to use for people that don't know a lot about computers. Put UNIX in front of those people and they wouldn't know where to begin - so whilst I accept it has a BSD core, OS X is not UNIX, merely a derivative of UNIX, since the command-line power tools that make people use UNIX are hidden from OS X users by default.
The people I know who switched to OSX circa 2002 were Linux users, not windows.
I don't know where you get the facts to make this statement from but it's not my experience. In 2002, the penetration of Windows XP was still very low, Microsoft was still suffering with negative backlash from Windows ME and if you wanted a reasonably good desktop Linux for the time then you had a choice of Red Hat, SuSE, Debian and Slackware (with maybe one or two others). None of these had much of the slickness and ease of installation that Linux distros do now, therefore if (like me) you were using them then, then you were probably a die-hard Linux geek anyway who was still using Windows for some stuff.
I therefore believe your statement to be false - people switching to OSX in 2002 were disillusioned Windows people, not Linux people.
Okay I know that last part has gotten better, but still every time in the past decade when I've gone to try Linux on the desktop again something hasn't worked without a workaround
Again, you're contradicting yourself. I accept you like OS X more than any other OS but OS X is specifically designed to run on a very small and specific subset of hardware which is why you can only run it on Apple machines. But then you complain that you find Linux difficult to install on a laptop that contains one of possibly thousands of possible combinations of hardware?
For your information, I recently bought a Lenovo laptop on which to run Linux and all the hardware on it ran pretty much first time with little or no difficulty. In actuality, I did a lot of research first, looked at countless laptop model specs and after a couple of weeks decided that was the model that would be the best one to work out of the box with Linux, in my price range and with the power and features that I needed. And that, incidentally, is basically the same process Apple do when they choose hardware to go in their Macs - so if you had problems with your Linux laptop then, sorry, that's your fault for not doing your research and going to ask questions from people in the know, and that's why you as a consumer have a choice of going to Apple who have done that research for you up front.
When Apple moved to Intel chips, well then we could run Windows via virtualization or bootcamp allowing people like me to have 1 machine, work, and test on both OSX & Windows.
But earlier on in your posting you said "OSX is the best of all worlds" - in which case you've again contradicted yourself by stating you need the capability to run Windows on your Mac. So which is it to be then?