Earlier quoted context omitted.
Except Linux users want all their software to be free.
Nearly every Humble Bundle release of games shows that Linux users spent more than Windows or Mac.
Also my first interpretation of the headline was "Linux users provide valuable feedback!", which matches my experience. I report so many bugs against everything all the time as a Linux user, if a game had a bugtracker I would definitely use it if I encountered a bug. Whether the issues were Linux-specific or not, I don't know.
Finally, my experience with cross-platform development is just not nearly as bad as I keep hearing. I do it. Bundle, and use an already cross-platform library for your GUI or graphics. I admit I don't make 3D games, but I'm super perplexed as to what is supposedly so hard about the cross-platform aspect of it. For my (non 3D) graphics I don't even use electron, just Qt (also perplexed by those thinking electron is the only way to do cross-platform). I've never tried to freeze my code so it will work on future systems (it is open-source and maintained to stay up to date), but I know exactly what I would do if I had to - I would bundle literally everything except glibc and the kernel and call it a day. Would anything trip me up if I were to do that? Am I naive and waiting to be burned by something I don't understand? Maybe - but it seems like the devs complaining about cross-platform development being hard aren't even doing this step.