Because Xbox exclusives are about console exclusivity, they release their games on PC day one. The other console makers are even less consumer friendly.
We'll see how many post-acquisition inXile, Obsidian, Doublefine etc. games make it to Linux/macOS compared to pre-acquisition, not counting those where they had contractual obligations to release Linux port (e.g. Psychonauts 2 was already sold for Linux via Fig before the acquisition) it doesn't look good so far.
