In good organizations, that's true. However, the Phillies have been known in the past to have key decisions made by box office people or marketing people as well. Chase Utley bobbleheads attract crowds, so it makes sense to give him an extension. Things like that.
Certainly, Amaro has been terrible for us. I'm just not convinced we would do better with a replacement without a change in organizational thinking unless the replacement is something with such a strong track record that he could command the influence to overrule the other players making these decisions.