I think this has been discussed a bunch way back when the whole - you can't run AOS except on a dongled board - thing came up and the reasoning behind it all was something like this:
It protects Eyetech's investment in producing a board to run AOS.
It protects Amiga Inc from having its OS (produced by Hyperion for OS4 with the possibility of another contractor in the future) from getting its code pirated.
It protects from having to invest heavily in board support of arbitrary platforms (in the way that MS or Linux have to do so much board support churn) so that they can work on features and bug fixes instead.
It hasn't worked out to be too stimulating for the market, but then again, what would be? Oh yeah, I forgot. Free hardware of a next generation spec running free applications far in advance of anything available on any other platform.
