The WTA, ITF, etc., really dropped the ball with their efforts to reduce and/or eliminate excessive grunting. It's a useful step to try and remove the noise from the junior ranks, but it was a total copout not to apply the same rules to current professionals. I can guarantee that a few "excessive grunting" calls resulting in forfeiting a point under the "hindrance" rule would "cure" most professionals very quickly. I frankly consider it cheating because it can mask the sound of the ball striking the strings and thus making it more difficult to read the shot.
And what will happen in several years when some of these junior players, who've learned to play without the grunting begin playing on the professional level against today's professionals who are still allowed to make excessive noise. One player will be allowed to excessively grunt and mask the sound of the ball while the other will not. There's a recipe for controversy.