Probably depends on what's being said. Good natured trash talk is great. I don't do it, but I think it's entertaining. Just my opinion.
As a pitcher, hitting middle doesn't bother me and I never tell my teammates to stop doing something that pisses off the other team(within reason, of course. Being vulgar, crossing the line, etc. wouldn't be tolerated). By the same token, I would never tell my teammates to hit middle to prove a point. If it's their natural swing, have at it. But middle wars are just stupid.