That just not true. "All Linux users dual boot" where's your data to say that? "Nobody compiles for Linux" factually false, many of the most-played games on steam are Linux-native, and most others run flawlessly on Proton.
And 1.2% is slightly more than half the mac market share on steam. Should mac users also be ignored?
But games that run on linux via proton have not been compiled for linux, so mentioning them as a counter-argument to games not being compiled for linux makes no sense.
The broader context here is TFA rejecting the "steam runtime" idea, and for proton-based games proton is that runtime! They don't need anything from the system because proton/wine provides it.
linux native + proton means "some compiles for Linux[1], the rest either tests on proton (steamdeck should increase that segment at least) or does not care"
And 1.2% is slightly more than half the mac market share on steam. Should mac users also be ignored?