Don’t know if apple would have gone vulkan if MoltenVK didn’t exist. But it’s kind of irrelevant. Metal does exist, and existed before Vulkan.
Fact is, they released Metal before Vulkan was even a thing. Apple saw a need, built their own thing and that was that.
So bitching and moaning that they didn’t use Vulkan… well. It wasn’t an option when Apple decided they needed something. DirectX wasn’t an option either. There was no open or closed alternative to fill the need so they built something themselves.
And now, there’s a shim. So you can use Vulkan if you like, anyway.
So i’m not quite sure what the problem is, other than people desperately looking for a reason to be angry.
You’re already going to have to use a bunch of proprietary APIs to code for the Mac in any case.
Dropping openGL is another issue. However - someone can write an openGL shim (openGL equivalent of MoltenVK to translate into metal) which it shouldn’t be a huge problem if required, because openGL is an open standard and metal is well documented.
But really. Its time to get off openGL for performance reasons, or competitors who do so will eat your lunch. Deprecating OpenGL is apple’s kick in the pants to encourage that.
Letting app developers be lazy and continue with openGL (because they can’t be bothered updating their code), when on windows they’re going to be using DX12 or Vulkan for improved performance is just going to put the application performance on Mac further behind.
This forces the issue. The developer either re-writes for Metal, MoltenVK, or the niche they filled is open to someone else writing a native Apple application.
You may not agree with that strategy, but this is Apple’s strategy for ensuring that crufty old application software isn’t carried forward. Similar to the way they deprecated Rosetta pretty quick to drop non-native applications with Lion.