If the only thing keeping industries in check is the president, then that ends the second that the president is no longer in office. It's one of the two fundamental problems with the idea of the "benevolent dictator" -- that's an unstable situation that ends as soon as the dictator is gone.

(The other problem is that a benevolent dictator is still a dictator, no matter how benevolent, and so is in complete opposition to the notions of freedom and liberty.)