"It would be really interesting to see Apple release Mac OS to OEMs"
Apple is an hardware company. It makes money selling its hardware at high prices - it would not be able to compete only at the software level. It tried to open to OEM and that was one of the deals Jobs terminated when it was reinstated - he understood Apple would have not survived as a software vendor only, especially since it basically makes the OS only (and very few other applications, some already killed like Aperture).
But in that also means choosing Apple you put all of your eggs in a single basket - you have only one hardware supplier available, and also a restricted choice of hardware options.
Biting the hand that feeds IT
