> When a game glitches because of a driver bug, its the game developer that gets the bug reports (and the heat) and often has to isolate the problem to convince the gpu driver-team to fix it.

Exactly, and having a Vulkan-only codebase won't make that problem go away. And IME it's much more likely to encounter vendor-specific driver issues on Windows Vulkan drivers than for D3D drivers.

Vulkan drivers on Linux are in a much better shape because they are centralized under the MESA project (except NVIDIA's drivers, which also have significant behaviour differences to the MESA drivers, at least in the window system glue).

> You may note that I specifically said "PC game developers" Your whole but consoles argument, completely misses the mark.

Why should a game developer support the tiny Mac market, but ignore the much bigger game console market though? From a business perspective, Mac support simply doesn't make sense, it's too much hassle for too little return (and the hassle isn't about the different 3D API, Metal is actually one of the best parts of the whole Apple developer ecosystem).