Just to be nit-picky here, but how would being a Janitor help Tim Cook at Apple?

My point is the usefulness of "personal experience in every role" is a bit, ah, debatable?

Obviously the Janitor example for Apple is a bit extreme, but where do you draw the line?

I hazard to say your statement is only applicable for small companies. Perhaps one where every role has a strategic or tactical impact?

Going on from that perhaps a better statement would be:

"It helps to have personal experience in every role of strategic or tactical value in the company before you become a CEO. I don't think it's necessarily a requirement, but it sure helps."

That said, I'm not sure that quite cuts it either...