MS does have a nicely integrated set of developer tools, but they are not particularly useful for people who aren't developing for a Windows platform. Most consumer-facing Websites don't run windows, nor do most cell phone apps.

There are plenty of Windows jobs building corporate software (think intranet web apps and desktop GUI applications) and so there are indeed many devs who build that stuff and enjoy doing so on Windows. I imagine there is an overlap between the Indian devs and the Windows-related dev jobs.

Personally, I build OSS-based web applications on Linux. My last machine was a Mac and while I enjoyed it I chose Linux this time around because of the lower sticker price and the better native integration with OSS tools.