It's because a lot of people bash MS OSes. A lot of people don't realize (or are in denial) that the typical user who wants to just learn to program only has one machine they use for a lot of different tasks. It's because of this prejudiced bashing (which I will admit I do from time to time, but not a message board) that MS OS users feel the need to sort of bow down to the ^nix users. I understand that the MS OSes were not specifically designed for programming and that there are better systems. At the same time, I don't want the verbal abuse that I have run across in this community over what system I run.
I completely agree that Perl is for everyone. For that matter, every language should work on every OS, but that's just me, I guess.
My 2c. on that. Sorry it's getting OT, but I feel it needed to be said.