No, I didn't. I said execs are replaceable...and they are. If you replace Tim Cook with a ham sandwich, it will make no difference to AAPL at all. It is very rare (I have never seen it) where the SP will fall because of a CEO leaving, it is more common for it to rise when a CEO leaves.
Again, it is important to realise too...there are probably no other CEOs that have made as much as Tim Cook. Even amongst execs, he is wildly wildly wildly overpaid. Corporate governance at AAPL is basically non-existent.