Not booing him as a person, but you can boo his performance. Booing has been shown to not improve player performance. See Patterson, Corey and Hawkins, LaTroy. Booing shouldn't make a difference one way or another. Those two were just plain bad and are still bad. By booing, fans voiced their displeasure, management took notice, and now they are gone. If a player has that thin of skin and can't own up to their own suckiness, then too bad for them.