This extends past linux. Open source projects get used broadly regardless of runtime environment. Steam is just one open nerve ending where this could be used for good and they have the power to do so (and from what we've seen, steam seems to be a low friction company, less corpo red tape - would you trust say Ubisoft with handling this or steam?). If a game gets deployed to windows, it doesn't matter, as each game/application probably use five or ten or more open source projects regardless of where they run. It can help open source devs keep pacing with steam and game developer needs. Remember a ton of these project have upstream effects outside of gaming - its just the most obvious open nerve we can use to help open source.