If Linux were just a niche platform, that would be fine. But supporting desktop Linux systems is disproportionately difficult -- it's a small niche, but it's a lot of effort. Userland APIs break all the time. The constant churn in the graphics and desktop space leads to a lot of instability and bug reports. Between Wayland being default on some distributions, unstable graphics drivers, and the umpteenth rewrite of God knows what other component in Gnome or KDE, you get to deal with the sort of bug reports and crash dumps that used to pop up fifteen years ago when a Longhorn beta was leaked and everyone tried to run their games on it for shits and giggles. Linux desktop is basically a neverending beta. People don't write games (or software) for it for the same reason why you don't write games for a leaked Windows beta.
It's no coincidence that Linux is such a big player in the embedded and server markets, but not in the desktop market. Writing desktop software for Linux in 2020 is about as enjoyable as chewing nails. It's an unstable and flimsy platform to target, and not a very profitable one, either. I can't blame any company for skipping it.
Edit: someone else posted this here and yep, it's spot on: https://twitter.com/bgolus/status/1080213166116597760 .