I started doing web dev before 2000. Only Windows worked as a dev machine then and OS X came around but obviously lack of third party tools made it a no go. Now I can't think of going back to Windows because third party tools that I take as granted aren't even avaialable with same level of quality on Windows.

3 or so years ago, I tried to set up a dev environment on Windows just see how good it can be then but gave up in 1 hour knowing it'll just slow me down bad.

I have no idea why most of people I know around still use Windows (and funnily 1 guy uses Linux)