I dont have a problem with that at all. A little motivation never hurt anybody.....this past year Jim Harbaugh taped all of the 49ers college recruiting profiles on their locker all season for the same reason. Lots of coaches do things like that. Hewitt is an awful coach, a terrible strategist and a poor motivator but cant knock him for at least trying with that tactic.
It's a little different when you are using a sibling. I mean could you imagine if Tom coughlin did that to eli manning when he was struggling? Hey I noticed your brother Peyton just threw 5 touchdowns last game, how come you can't beat him?