Well yeah, it always comes down to money. Even on an indie level Linux support is a commitment.
https://reddit.com/r/gamedev/comments/e2ww5s/mike_rose_linux...
Now if you do care about quality, having a committed, technical audience giving quality big reports is a godsend. But that's not where we are this decade rife with layoffs and rampant outsourcing in the industry.
You’re posting an argument from 6 years ago. Not including Steam OS, the Linux market share has almost quadrupled since then (to ~3.2%); including Steam OS, it’s up to ~24%. And continues to trend upwards.
You also don’t need to arbitrarily support Linux. It’s not difficult to say “this has only been tested on Fedora, Ubuntu, POP, and SteamOS; other distributions are unsupported officially”.