There are a few reasons why a mac wouldn't make a good reference platform. Besides Apple changing hardware/firmware setups between every release, it doesn't hav

There are a few reasons why a mac wouldn't make a good reference platform. Besides Apple changing hardware/firmware setups between every release, it doesn't have much official documentation and support for developers making an OS for it. Many people go to great pains to make linux run well on a Mac, especially hacking around the UEFI bugs that are present (not that they don't appear on other platforms either). You also don't really want a reference plaform for linux, because as soon as you specify one, you might start making decisions which only benefit that platform. This is bad for the current eco-system, as it could impact linux's ability to run everywhere. PS. Not to mention that Macs ship with broadcom wireless cards these days, which don't have very good linux support.