Precisely, and developing for Windows is much easier than Linux anyway because it doesn't suffer from the same "lets break userspace every 2 years" problem.
We didn't port our game Void Bastards to Linux because the sales are _so_ low we won't see a return on investment. Yes its easy these days, but there is still a few days messing around with builds and a few days testing. There is a good chance we won't see a week of salary as a return.
If you see how hard of a time publishers have to get their games running on the wide range of Windows PCs, especially at release, it's easy how they don't want to add a second operating system to the requirements as well.
There are sometimes problems, sure, but compared to Linux, where an application compiled 2 years ago for the same distro often won't work on the current version, it's pretty damned good at compatibility.
Age of empires 2 works out of the box on windows 10 ... The game was compiled with Visual Studio 6.0 ... Even that still runs on Win10. So yeah, it's pretty damn good.
> where an application compiled 2 years ago for the same distro often won't work on the current version
Ship non-system libraries with your application instead of assuming they will be in /usr/lib* and that's a solved problem. Valve even does that for you with the Steam runtime.
This isn't any different on Windows - if you don't bundle your dependencies (including MSVCRT / .NET / whatever) then you will run into problems.
As long as the game runs fine and it is supported, that's perfectly fine for me. Most ports use ad hoc emulation layers anyway that never see updates once released, while proton see continuous improvements (but of course it can also regress).
The better ports use the native APIs of course, but are few and far between.
Sure, but my point was that this shows the value in making a game that's easily portable to begin with. This is more for future games rather than converting existing ones.