As someone who has played a lot of games with native linux "support", I want less of it.
In nearly every instance of these native ports, switching to using the windows version via Proton was a better experience, either because the Linux version was outdated, unmaintained and buggy, or it simply performed better.
Annoyingly, as far as I can tell, Steam these days doesn't make a distinction between native ports and Proton games so it's hard to tell if I'm getting served the unloved child version until something goes drastically wrong and I have to start messing around with it.
Any kind of port can be of high or low quality, though.
Sure, I can see that. My solution to that one day will hopefully be to make sure devs can keep their linux platforms updated, not give up and go around it with a windows build.
But Proton discourages that, not encourages. As you said, Steam doesn't want you to know what build you are playing, and if the audience doesn't know, then the devs won't care either.