The problem is apple actively working against the game developers, or they just ignore the market completely. See the example of vulkan, and deprecation of 32bit games. It doesn't matter how good the hardware is. If the platform is not supporting the games and all they have are the occasional courting of the some of the games, the games won't come to the apple platform for free.
Also they are already making the mobile gaming money which is already lucrative. Are they also committing enough to the 'conventional' gaming?
The App Store is the real issue. Apple's antipathy towards developers is perplexing. The number of stories I've heard about companies having problems due to some interpretation of their policies is ridiculous. There are even horror stories about businesses going bankrupt simply because Apple decided they were in violation of something and banned them from the App Store entirely. I mean, no game company wants to spend millions on a game only to have all of their games pulled because one of them was too similar to someone else's game or something (according to some Apple reviewer with way too much power!).
Apple is justified doing whatever they want. I even agree with apple's stand that traditional gaming market doesn't matter to them. But from the traditional developers' perspective, Apple system is hostile and they have no reason to develop for Apple. Valve go out of their way to develop proton which is based on vulkan. Apple could utilize it if they have supported vulkan. Valve actively expand the linux support for old and current games. Apple has to work for it to court the traditional developers. Superior hardware doesn't mean much when the alternatives are good enough
And it's justified, because it's really not that important in money making in grand scheme of things.
Also they are already making the mobile gaming money which is already lucrative. Are they also committing enough to the 'conventional' gaming?