I'm a staff member on Freenode, an OSS-centric network. I also share knowledge Freenode's ##windows channel; and I think I can take a fair amount of credit for growing that channel from a dozen idlers to average well over 200 active participants in any given day.
Contradiction? I don't think so. See, I believe in choice.
Honestly, I do not think Windows is better than Linux. I don't think Linux is better than Windows. I use both operating systems liberally. Some jobs call for a framing hammer. Other jobs call for a nail gun. Two master craftsmen might disagree over which tool is better for any given job, depending on their style of workmanship or familiarity with one tool or the other. So it's not just about which tool is technically better, it's also about the comfort level of the tool user. Operating systems are not much different: the choice of OS depends more on the person and the job at hand than on the logo at the end of the taskbar.
While I don't see any need to derive a sense of identity from which OS tribe I belong to, there seem to be a few folks who do. As far as I'm concerned, that's fine too. But I do draw the line when it comes to spreading misinformation as a way of making your favorite tool look better than the other tools in the box. If you like your tool and can do great things with it, then where is the need to lie or down-talk the other competing tools? If your tool is clearly better, then this will become obvious. Maybe not as soon as you like, but it'll happen. Lies, mud- and fud-slinging will only slow down the process. Who wants to be part of the fudslinging tribe?
On the topic of OSS vs proprietary software. Again I use both, and again I hold the middleground point of view: I think choice goes to the author. I've never written and released anything larger than a script, and I happily give those into the public domain with no license at all. But if I did happen to write a piece of software larger than a script, I'd sure like to have the choice of whether to sell it for money or give it away for free. Please don't bother to angrily inform me that I can give away the product and sell the support. I'm fully aware that this option also exists, and I'm happy it exists - as one of the many choices a creator has.
I like open standards. Personally I lean towards products that work with other products. But again I recognize the right of the creator to choose which (if any!) standard she will follow in building her product. Just as I recognize the right of any person to decide which products (and therefore which standards) he will use.
When all the shouting is over and done with, I'm glad that people have choices. Creators have a choice of whether to sell their products and services and/or how to sell these things. End-users have choices about which products and services to avail themselves of. Value is where you find it, and price is measured in more currencies than just dollars and cents.
I want people to have more choices - and I want them to have access to solid, factual information on which to make their choices.