Arrogance...
Instead using ZFS they build new file system from scratch (APFS)
Instead using Vulkan they build new Graphics API from scratch (Metal)
Keep this up and they will end like MS.
Keep this up and they will end like MS.
No doubt there is reasoning in there besides the "we are an evil company" logic - Apple developers are people too...
Apple not only ignored first major consensus in Games industry it also blocked support on its devices. It also stuck with old OpenGL. This will make gaming on Apple to suck for many years to come.