I think you're an MS fan the same way I think Beep is a Republican Party fan. Sure, you see the same warts with MS and their products that everyone else sees. It's just that you're the one who defends them.
If someone slams Philadelphia, I might take the time to defend it. If they slam Cleveland I probably won't. And whether I do or not in either case will probably have more to do with my mood than with the validity of the slam or the merits of the city.
Bottom line is, there are lots of unfair or misleading statements made here all the time about all kinds of products, people, companies and issues. The only ones you (seem to) care about correcting are the ones against Microsoft. That doesn't make you a shill, or an apologist, but it does IMO make you a "fan".