Jeff Atwood giving up on Microsoft? Holy cow.
There is a huge gulf between Microsoft and Unix developers. I somehow missed walking down the Microsoft road, since I'd started on the Apple II (BASIC, 6502 assembly, Pascal) and never had an IBM PC way back. Then when I got to school it was Tops-20 and VAX/VMS and a little bit of Unix here and there. And by the time I got a PC, it wasn't to run Windows, but rather SCO XENIX on my 286.
I thought this was going to catch up with me around '93, since it looked like Windows was going to kill Unix dead. And then I'd have to start over and learn all this msft stuff. But no, the Internet came along, and suddenly I could code "client server" cross-platform GUIs with print statements. Thank f'ing god I thought.
And it turned out Unix seemed a whole lot better suited to server software, having been designed as a multiuser OS from the beginning. There were horror stories of startups paying 24/7 operators to sit watching banks of NT machines and rebooting them when they froze. And the initial failed attempt to migrate Hotmail off of unix when it was acquired by msft. Whereas we'd routinely get uptimes of hundreds of days on our unix servers. (Heck, the uptime for this machine is currently 158 days.)
At this point it doesn't seem to come up much anymore. As Jeff points out, there don't seem to be many web startups running on a microsoft platform. When they do crop up you know their tech isn't likely to be very strong. You see nonsense like Dipsie supposedly being "the next google" but then hear they're coding everything on microsoft and you don't have to pay any attention anymore since you know there's nothing there. There are the odd successful standouts like Fog Creek shipping actual PC apps, but they seem increasingly rare.
You can probably even avoid buying the usual raft of PC stuff on the business side now. It's thousands of dollars, installation and maintenance are a pain. Raw linux could be a bit much for a bizdev or marketing emp to use but OSX + google apps is probably a good enough replacement.