My guess is the same reason I felt compelled to click on the link. OS X is the best desktop Unix experience I have ever had. It has all the tools I use, all the power underneath, and it comes wrapped in a pretty pretty wrapper.

Linux to me has become a loose term for any Unix. I've heard it used to refer to any of the BSD's, Solaris, and even OS X.

Because of the false assumption inherent in the question.

keep it civil please