I'm quite capable of working with Windows and do it when I must, but not when I have a choice.

My programming experience goes back to assembly language for the IBM 650. I wrote the fastest math package for the PDP-1, I've been a UNIX trainer, I've written the innards of operating systems and taught others how to do it in graduate computer science courses, I've managed departments full of programmers. That's not the issue: it's that my time is too valuable, to me and financially to my clients, to waste screwing around with Windows when I can sit down at a Mac instead and be more productive instantly.

It's not how productive the computer is. It's how productive the computer makes the person at the keyboard.