There are really 2 issues. Both relate largely to the Tour caliber players and then have ripple effects on GCA and lesser players. The first is the impact on architecture. If perceived differences in distance cause classic courses to be lengthened this impacts on cost, slow play and design integrity. None of these factors is improved. If we could be certain that classic courses would not worry about the play of pros and their ability to challenge them, this factor would go away. But the proliferation of redesigns to keep courses "relevant" gives little hope that this will happen.
The second factor is somewhat more subtle and relates to the nature of the competitive game. Without entering into the discussion of "why" players are longer today, and the relative weight to be given to the various factors, we know that tour golf is a very different test than it was throughout history. The best players, at least since the advent of the steel shaft, always had to show proficiency throughout the bag. Indeed , the ability to hit accurate long irons was a key determining factor separating many of the best with Nicklaus being a prime example. Of course great putting was always an equalizer but the real players were good through the bag. Today, long irons come into play on tight driving holes, very long par 3's and sometimes for 2nd shots on par 5's, that is those where a mid or short iron is not required. so the skill required has changed and, at least to my mind, been dumbed down to a degree. I suppose we could build courses only for the tour which could be stretched out long enough to create the test but to what end and how would they survive economically?
Finally, unless people stop watching, why would the tour want to change. If the ball were made to go shorter, the manufacturers could no longer advertise based on distance (I know with the current rules they shouldn't now but an overt reduction would kill the "pitch") If that were the case, endorsement dollars would be significantly reduced and what organization of touring pros wants that? Finally, notwithstanding its huge war chest, the USGA has never taken on the manufacturers. In the Karsten case, it didn't have the reserves and folded notwithstanding its excellent counsel's advice that it would prevail against Ping. That opened the floodgates and, notwithstanding the recent publicity, I will be quite surprised if it finally "stands up'.