Apple couldn't get the volume out of PPC that they needed, and when Jobs did come back he killed the clone market and made the Intel push - with a lot of niggling issues the entire way with Intel itself.
Jobs wanted X chips at X price that was far under what any other vendor was given deals wise for that sort of bulk, but they did manage to get to common ground and I suspect Apple and Intel are both glad of that. More inportantly, I think Jobs likely made some threats in a paper tiger form that he'd flip to AMD or another x86 vendor and Intel simply called his bluff knowing Jobs would never have settled for anything but the "Cadillac" of the chip vendors, which was and still is, Intel.
Most of this is well documented in the various books and rags of the era.
