They are. You're mad that Valve isn't militantly enforcing Linux-native games, which is nonsense. The OG Steam Machine did that and was DOA.

Thousands of game studios are gone now, and supporting their software is important legacy work. You don't have to appreciate that, but I do. I do not give the faintest fuck about the opportunity cost you bemoan towards native UNIX games when I do this. That's your problem, not mine.