You're right. If you can't change everything, might as well not even try to change anything.
Pitches being weapons and benches clearing are exceedingly rare and the players are punished accordingly. Cursing and drunkenness and violence in the stands also isn't tolerated, even if it does happen. The league or the stadiums don't condone that stuff, which is entirely different than allowing a player to enter to some smutty song (I have no idea what the song is).