Earlier quoted context omitted.
Have you not seen Steam Play these last few months? Because of Proton the majority of the top 250 highest rated games now run fine on Linux. I've been playing Skyrim, Witcher 3, Dark Souls 3, Castle Crashers, Overwatch, Heroes of the Storm, etc all of which are Windows-only but now WINE is so good it runs like it's native. Linux gaming doesn't suck anymore and it's coming to eat Windows lunch. Check out ProtonDB to s…
You know WINE exists 25 years though. During this time, Windows still has 95% market share ( https://store.steampowered.com/hwsurvey ) You could also think that, because of WINE, Windows is first class and then they check Linux with Wine. Depends on the perspective. PS. Yes, steam detects Wine
By making Linux compatible with Windows games it gets rid of that objection "I'd move to Linux if it weren't for my games" which was the remaining objection for a LOT of people.
Because Steam tracks WINE that's a very good thing, so they can detect players who bought their games to play it on Linux.
This helps encourage Linux native gaming growth, because developers can see the chunk of Linux players rising as more get rid of Windows because they no longer have that remaining obstacle.