You pay extra for the unlocked multipliers and you are still limited by the temperatures. The guys who make them are not stupid to let OC using just stock air cooling achieve the same performance as something almost 2 times more expensive.
You are misunderstanding something here. We are not talking about if Intel allows OC to be done or not, but just how much you will gain from doing it and how they can turn that into profit. No company will willingly destroy their own product line just to please the 1 guy in a million who likes to OC.
First off, I sincerely doubt that , "one in a million", attaches to enthusiasts who frequent places such as Techspot.
Second, there is something to be said for the credibility of the, "Intel does things as cheaply as possible", camp.
If you follow the progression of their stock coolers, once upon a time, they had copper cores, pressed into the aluminum radiator assemblies!
OK, granted those Prescott P-4's threw off a lot of heat. But, I have an eMachines T-5026, w/ a P-4 519 3.06Mhz. Now, I certainly don't overclock this junker. That being said, even Gateway didn't trust the stock coolers of the day, and the computer is fitted with an after market bolt-me-down cooler. No push pins!
Every time Intel has made and improvement in TDP, they've chopped more and more aluminum out of those stock coolers.
But you would think after all of the heating complaints they received from Prescott P-4's and the junk 9xx series dual core CPUs which came after them, that they would have condescended to leave a little extra metal in the stock coolers. But no, now they're down to probably only a half inch thick, and still get thrown away right off the bat, in lieu of after market coolers, whether the builder is going to overclock or not.
Since we're on the same topic of heat, Intel further tampered with the cooling by no longer soldering the lids on. Which AFAIK, did provably work better than TIM between the die and the lid.
It comes down to wondering whether the engineers at Intel are getting obnoxiously cocky about the low TDP of today's processors, and consequently cut as many corners as they possibly can.