Back to the original question:
Amiga os1.X, 2.X, 3.x, why not running on old 68k macs natively? The answer will be the same.
Of course it not much work to boot os4 on macs, but 1 or more years ago, when acube tried to wrtite some bootloader/etc to running os4 on macs, there were not working sam440 boards. Now they have. And i think os4 running on it, just the lawsuit, you know...
And it will be a true suicide to compete with their own products now. (moana versus sam440+os4)