Like many of you here, I hate Windows and havn't used it on any of my computers in years (as in since windows 98 stopped being supported). I used to use it for gaming, but I found Gnu/Linux games to be "good enough", and I just didn't want to deal with the hassles of DRM such as always on for single player games, windows updates breaking stuff, and concerns about windows getting broke,having to reinstall and it worry about activation (if I break my linux install, I just can reinstall it and no one cares about "activation")
On the other hand, when making games, I get worried about how I make this cool game, and I don't know what percentage of people are using Gnu/Linux now, but my understanding is percentage wise the number of Windows users are greater. So, while Linux is a lot of users, I realize if it ran seamlessly on windows, it would have more users. I sort of got around this by using Java, but that's only for the client and editor portion of my game, the server is still in C. I figured, eh, to run a server you might just want to be a system admin and use Linux anyway on one of your machines, but of course that doesn't do much good if you don't have a persistent set up server.
I know there are a lot of people just getting into Linux who still have a Windows install around, as well as people who primarily use Linux as another thing to use in order to practice system administration skills, and I know there are things like mingw and cywin or something that runs on windows and makes Linux stuff run on windows, but for non-technical users, it sounds awful complex.
I worry my free software zealotry is driving people away and just getting them annoyed with me so they don't want to hear anymore. I don't actually want to use windows again. I have so much work on my game, that I'm not sure trying to make it all work on windows is the best use of my time, since those people are pretty non-technical anyway, so as far as contributing to it, they probably aren't the most useful even though as players they are just as good as Linux users.