They're in the most physically and mentally demanding position in their life thus far, if you don't think players need motivation to give 100% effort all day every day then your kidding yourself.
Ever hear of bulletin board material? Ever watch Jim harbaugh scream his face off on the sideline at his players? Those locker room speeches? It's all for motivations sake.
I agree with you. But the great ones don't need motivation. And this was the book on Coples coming out of college. This is also the second straight year where his coaches have called him out. He is a very talented player but he has some dog in him. Plain and simple.