There is a reason why he gets buried in the bench. His quickness provides mismatch ups but his defense is a liability. With Harden's poor defense, we can't afford poor defense from PG. Lin already gets enough blames for not being good enough. Brooks would be just worse. Beverley was the better backup for the team.
Essentially, even in the playoffs with Lin out, McHale was quick to leave Brooks on the bench even when he was showing some offense. Outside of Harden who McHale has to play, if you can't play defense he is quick to drop you.
