Honestly, there really should be more linux support by game engines. So far, the only popular game engine that supports linux is Unity. I think crytek has basic linux support at this moment (not too sure on that). Unreal currently doesn't support Linux natively.
Unless the game devs scripted their own game engines, it's not up to them whether or not to port, it's up to the game engine they're using.
Elite seems to use it's own game engine. Pretty neat. I'll sign