I expect that Apple has some code buried in OS X to ensure it will only run on their Intel hardware. They make their money from the hardware, not the software - unlike MS.
Oh, running Windows on a Mac is dead easy. Apple has their free "Bootcamp" software and their are a few commercial products as well.
Edited to add -apparently it can be done.
http://www.macbreaker.com/2014/01/in...th-niresh.html