Re: making it longer. I think it was pretty much spot on in terms of length. This is a speech at graduation/commencement, nobody wants to hear someone yammer on and on and on. He had a point, which he illustrated with 3 concise examples (Liar's Poker, Moneyball, the Berkeley study). He could elaborate, certainly, but I don't think this was the forum for it. Maybe he'll find a venue in which to elaborate at some other time, but I think this pretty much perfect.