I'm sorry but the statement that Amiga's licensing terms are preventing the same thing from happening with AmigaOS is grossly misleading.
The fact of the matter is that Apple was already paid for an OEM version of MacOS when these machines were bought.
The fact of the matter is that NOTHING prevents anybody from doing exactly the same which is buying Apple hardware and reselling it with AmigaOS provided the hardware is certified by Amiga (which should not pose a problem).
As a personal note I would like to add that Apple hardware is so clearly branded "Apple" (typical Apple design etc.) that I as an Amiga user would not take any particular pleasure in running AmigaOS on a desktop machine when a valid alternative in the form of the AmigaOne is available.
