Bots
I used to be in several groups of roughly 300-500 people. Of course not everybody talked but there were the usual active users. Then bots became prevalent, as did bot spam in those groups even among inactive users. The bot spam became so bad it started to make me lag. I am no longer in any of those groups, and only ever really use this app for private messaging my friends. If I could talk them over to something better like Kik then I would have dropped this app like a rock the second they decided they needed to make everything ugly and teal.
Mr. Horris about
Palringo Group Messenger - Chat & Play!, v7.5.2