> I'm open to the possibility that something actually did change about the business landscape ... such that it's in fact true that there's a big advantage to hiring from the small pool of acceptable CEO candidates that justifies giving them entire train cars full of cash...

Even if there was a big advantage to hire from the same small pool of acceptable candidates, that's no justification for paying them "entire train cars full of cash." There's all kinds of scarce and valuable skills that are just as rare but compensation doesn't shoot off to infinity.