This didn't need Microsoft's teeth to fail. There isn't a single "Linux" that game devs can build for. The kernel ABI isn't sufficient to run games, and Linux doesn't have any other stable ABI. The APIs are fragmented across distros, and the ABIs get broken regularly.

The reality is that for applications with visuals better than vt100, the Win32+DirectX ABI is more stable and portable across Linux distros than anything else that Linux distros offer.