The problem you're running into is that games are a completely different ball game than any other type of software. Operating systems, office suites, browsers, etc... are all useful to a large group of people, and are necessary to be productive. As while games are there almost completely for entertainment purposes. So as while a developer working on Firefox for example benefits from working on open source by also having a great browser for their own use, the same can not be said for games. Even Richard Stallman has acknoleged that gaming is a different beast to some extent... so in reality, youre probably not going to get very much QUALITY artwork free of charge, nor levels, voice acting, sounds, and so on... but the game's engine is the one place that still benefits from open source like any other software. And really that's the most important part as you'll always be able to have the option of porting past games to future hardware and operating systems. Besides rip-off FPS games and stuff like solitare, it's about the best situation you can hope for.