Since when was public match FFA snipers only?

In ~90% of the FFA lobbies I join, the entire lobby is sniping and they rage at me for using my smg. Since when was this a thing? Why am i expected to snipe? This aint a private match. Joined a pregame lobby a bit ago and one guy was like "X is a reg (regular) gun user, ima leave." Apart from the voice chat rage, i keep getting messaged on psn too. Im confused why im getting so much hate. One guy responded to my confusion saying "its ffa, get with the program." I love FFA and have played it for years. Where has this unwritten rule come from?