I can see where the higher ups, and some players don't like it. You have a hard time hearing the ball hit the racket, and it can be damn annoying. They were talking about how old school players like Navratilova cannot stand it. I guess they feel that it has gotten bad enough where they are saying the line judge will have a noise monitor on the court to see if it gets too loud.
On a personal note though, I enjoy it myself. Closest I've gotten to hearing orgasmic grunts in about 10 years.