I really don't think that the flaws in management you see are the fault of Zuck's youth; the flaws you see are the result of his character. The reason you don't see these flaws in equally-prominent fortysomething executives is that all the ones who have characters like that have failed so badly for so long they're off the radar.
Let's just put it out there: At the exact moment that it's poised to dominate the world, Facebook has jumped the shark. With over 100 million users, even your dad — who's probably as old as Fonzy — is on the social network originally meant to get you laid in the dorms. Today's featured commenter, raincoaster, has a theory about what's wrong: