Apple won't support it, therefore support and maintenance will be working around apples proprietary hardware and special drivers. Linux is not meant to live in that environment, I'd argue bettering support for other OEM's is a more fruitfull goal.
Linux is like the cockroach of the OS world, it can do just fine in any environment. After the apocalypse, I'm pretty sure the OS the cockroaches are going to use.
If it hadn't been for reverse engineered proprietary drivers, Linux would have never gotten to the point it is now.