Alan: forget the architecture and think of the externalities -- namely, standardization. (Or would you rather live in a world where CP/M-style incompatability reigned unchallenged?)

I'll grant you that an IBM PC design that came out a year later and used the 68000, VMEbus, and Xenix would have been one whole lot nicer. But it would also have cost too much to compete with the offerings from companies like ACT (remember them?) or Apricot (in the UK). A good idea? You be the judge ...