It's a Troma film, so the studio revels in poor taste cinema and I think it's just to further portray those characters as the "bad guys", the bullies who will get their comeuppance...
Circus Circus is correct about Troma less than stellar taste. But the character have a game of torment and mayhem. They are given points for running over bicyclists and beating up old ladies with walkers. Just pointless sadistic fun.
Great movie, just real bad taste on ways to fill in areas of the film.