I think it's great. Brings excitement. In all other sports fans root for the home team, or for their favorite players. This is what sports are about. Why should pool audiences act like they're in a library?
I don't think they're being rude or inappropriate. If they were yelling right when a guy was about to shoot, or shining lights or jumping up in down to disrupt players, that would be different. But they're not.
What they're doing is cheering good shots, gasping at bad shots, and "oohing" and "aahing" whenever someone gets out of line. It's great. It's exactly what a fired-up pool audience should be doing.