Except that it's (1) not a pile of crap (it actually works unreasonably well, and keeps improving) and (2) building for one platform and having third party tool

Except that it's (1) not a pile of crap (it actually works unreasonably well, and keeps improving) and (2) building for one platform and having third party tooling make that work on other platforms means you are not spending five, ten, or even more times as much on purely supporting additional build targets. No sane PM would go "hey let's take a huge chunk of our budget and spend it on native builds and QA for at least five different-enough-to-all-have-their-own-bugs linux platforms in addition to Windows, rather than spending it on actual game development for a single platform".