Well, even for BootCamp, a marketed feature, they only dropped a halfarsed set of drivers which worked very poorly and were pretty never updated. We need to use hacked AMD drivers to get updates for the Radeons and the Macs still overheat and burn a lot energy due to lack of even basic power saving features. Heck, even the GPU switching isn't implemented.

Why would there be expectation they'd do anything more for Linux?

Apple is turning into a services company, though, look at their numbers.

And one of those core services is the App Store.