If I recall correctly, in the begining there wasn't a cooldown on them, or if there was, it was for a shorter period of time then they are now, and they could be used more often. There were people everywhere using them repeatedly on the same person over and over again. Then the complaining started, by everyone!
You have to remember, this was 2 years ago when we first saw these emotes, if not longer. People started dreading festivals, due to those prank emotes. Something needed to be done.