"it's becoming increasingly clear that at Apple the CEO calls the shots,"
Becoming ? When was it ever not clear that that was the case ? Or rather, when was it ever not clear that Apple is Steve Jobs' personal vehicle for delivering his one true vision of the way we should compute ?
Jobs is a micro-managing sociopathic control freak, and inside Apple he has ALWAYS called the shots, even when he wasn't the CEO and the actual CEOs have tried to keep him out of the way. Christ, even when he stropped off to found NeXT you can bet he had an eye on coming back and staging the coup to make Apple his again and make them do things HIS way.
Anyone who is only just becoming aware of this fact has not been paying attention at all for the last thirty or so years.
"And that's exactly the opposite of the way corporate governance is intended to function. A company's CEO is supposed to serve at the pleasure of the board and to answer to the company's investors - not the other way around."
Yes, that's the theory. In theory, theory is the same as practice, but in practice it isn't. Stopping board members from interfering is an art unto itself, and a widely practised one at that. Jobs has an easier time of it than most people who have to deal at board level, because a) he got pick the team. and b) he is a notoriously charismatic sociopath. Or so they say, it doesn't come across in his public appearances.
"might become an autocracy"
Might ????? Nope, to late, it's been to late since at least 1997. It's probably been to late since 1976.