Unity does have Linux support, it’s just in beta versions at the moment, here is the 2017 version: http://beta.unity3d.com/download/b6e0e521da90/public_download.html and here is the forum thread discussing all the Linux versions: https://forum.unity3d.com/threads/unity-on-linux-release-notes-and-known-issues.350256/
I’m not sure how well Unity games work on Linux, I know Unity does support Linux builds although I’ve never played any of them myself.
Creating general purpose game development courses isn’t really going to help anyone. At that point it’s mostly theory. It would be similar to teaching general 3d modeling without being specific to any program. It’s tough to go deep with that kind of content. If you have something specific in mind let us know. People have mentioned the Blender Game Engine which isn’t very well supported so we don’t teach it. Unreal Engine is also another, but I’m not sure how well that works with Linux either.
Personally I think building on Linux is more trouble than it should be. A lot of software you may use in game development is probably not Linux compatible and you may run into a lot of snags just to get things working properly.
