The board does have the legal ability to fire the CEO, provided that it passes a very bar, such as being able to prove mental unfitness, etc... which wasn't the case here.

On the other hand, if you're arguing that a board should be able to fire the CEO without cause and have him barred for eternity, then you're arguing that majority shareholders shouldn't be allowed to serve as CEO - in a private company !! - which has been the basis of capitalism for ever. It would destroy the economy as we know it.