Especially because devs actually have to go out of their way to exclude Linux these days. Proton makes it so damn easy to support Linux. If you don’t, it’s because you did not even try or you intentionally added some bloat to your software to make it incompatible.
Eh maybe some do it on purpose, but I realized over the decades of my life that blatant incompetence is scarily common.
Not only proton, but unless you are rocking custom engine, pretty much all of them support Linux out of the box. It’s usually middleware that poses an issue and most importantly developer’s inexperience with the OS, which means they can’t provide tech support for their product.