Besides the technical arguments, there are the philosophical ones. Linux is open source, it is not controlled by one company, it usually doesn't send your data to some server which then sells it to advertisers, you have access to the source code of mostly everything if you ever feel the need to dig deeper in its understanding or modification, etc.

But for game dev specifically, Linux may lack some of the specific tools you guys use. While GL/Vulkan debuggers and utilities do exist, some proprietary Windows stuff may be difficult to emulate in the Linux environment. I do know some of the game dev tools also work on Linux, and Mesa gives you a lot of power in debugging shaders, but that's all I know. You can also GDB your Mesa calls to know exactly where you application is failing if you need to.