My only maxim in life is to question everything. Do you really think Apple would go out of business by selling their OS to everyone? Is Apple dependent on Mac sales like they were when they first licensed clones? Do you think what was true back when Apple first tried licensing clones is true now? What has changed since then? Does everybody saying the same thing make it true or untrue? Or are those people merely sharing an opinion?
You ask for proof to a hypothesis that hasn't been tested, and assume you have proof to the contrary even though the control conditions are different than before. Jobs himself cited Apple's dependency on computer sales as the undoing of the clone program, and now, courtesy of the iPod, the iPhone, and the iTunes store, that dependency no longer exists. Those facts you cited don't apply to the current scenario; it was Jobs' opinion that it was not possible to succeed in licensing Mac OS, but times have changed and I feel that it would be worth their while to try again. I can't prove whether it would work or not but it looks really good on paper. If you want proof, I guess the only way we'll know for sure is if Apple gives it another shot, so it's really up to them to find out.
At any rate, I'm willing to agree to disagree here. I questioned everything I could, looked into every angle presented, and came to my own conclusion based on reason, logic, and google.com; as I said, I've heard all these arguments before, over the last two years, and it seems no one can offer anything fresh to make me question my opinion on the matter. I think Apple stands to make more money overall licensing Mac OS X for PCs than not and I think not offering Mac OS X for PCs is their way of forcing hardware sales on consumers who want to run Mac OS X instead of Windows, even though Mac OS X sold by itself has a higher profit margin even if offered at an OEM discount, due to the inherent nature of how any software's profit margin increases for each copy sold, and volume sales to PC users and vendors over time would net enough profit to more than make up for any possible loss, if any, incurred in hardware sales as well as increasing their customer base dramatically, creating further sales potential and strengthening the Apple brand as a whole; take it with a grain of salt if you must, but that's just my opinion. You are entitled to have your own.