Unfortunately, players have been doing that since the beginning - they used to do it in the three cities (Ul'dah especially), and it wasn't just DRGs either (although they were probably the worst offenders). As others have said, you can disable battle animations/sound FX made by other players but it's the principle of the matter. You shouldn't have to do that simply because other players like being obnoxious and spamming abilities in the middle of a crowded city.

It's like doing a burn out in a carpark in the middle of the day - simply to show off and be a tool, while annoying everyone else around them. I agree that SE needs to lock the use of these abilities outside of a battle, as there is absolutely zero need to use them, other than to deliberately annoy other people. *equips flame shield*