People come to see the players. Nobody ever bought a ticket to see a manager.
It isn't enough for an umpire to merely know what he's doing. He has to look as though he knows what he's doing, too.
In a way an umpire is like a woman. He makes quick decisions, never reverses them, and doesn't think you're safe when you're out.
Officiating is the only job in America that everybody knows how to do better than the guy who is doing it.