Serve and S&V became too dominant in the 90's. Goran and Sampras turned Wimbledon into ace fests. Public was getting bored and in order for the sport to take a step forward and keep its popularity the surfaces HAD to be slowed down.
Serve is still THE most important shot in tennis today, just not AS dominant and that is a good thing. Lesser reliance on serve forces the players of today to be more athletic, more fit and to develop the technique of groundstrokes. The entertainment value of tennis has gone up significantly. People longing for acefests have forgotten how boring such matches were. One break, one mini-break and you could lose a set. It wasn't fun, didn't have any drama or suspense.
Agassi won Wimbledon in 92 and 'big servers' Rafter, Courier, Becker, Pioline all got to finals. Some baseline hitters actually did pretty well. Pete was just too good.
As for the public was getting bored, not this public here. Ivanisevic-Rafter is still the most loved final in a poll by the BBC and 2001 the favourite recent tournament.
As for that, take the last line out. It's all about athleticism and fitness now. Ball striking ability matters little. Look at the Nadal-Nalbandian match in the once fast US Open a couple months back- Nalby painted the corners over and over and over and over and yet the ball somehow was still coming back on a tournament that was once fast. That's how homogenization has destroyed the game.