I think the deal was that the Mac was never really a hardware-centric system to begin with. C64, Amiga, Atari, even the IBM PC had a defined hardware standard that democoders could rely on so that they could work as close to the bare metal as they felt comfortable with, which was a big advantage in pushing this or that machine to its limits. The Mac, on the other hand, didn't really bother with standardizing the hardware, since the idea was to use the System and Toolbox exclusively and let them worry about the differences.