My two options are use Linux, binary nVidia drivers and a commercial game engine or use Windows. Which option sounds more open to you. Unless you can find me FOSS Drivers that support OpenGL 4+ and are competitive with windows performance and a game engine that is in the ballpark feature wise with Cryengine I don't have a third option.
Spending time and energy making FOSS better is what will win the war if you want to call it that. Insisting that everybody should use FOSS software all the time doesn't really do much in my experience except add noise to the conversation and scare off people who would otherwise benefit from and benefit the FOSS Community.
Interesting statement. And how exactly will FOSS software benefit from more proprietary software and more proprietary software users?