Hip hop was a diverse genre which had political messaging as well as party themes.
Then along came drug lords from CA with their gangsta rap crap. This portrayed to stupid upper middle class black boys that they only way to be authentic was to be a gangsta. It showed stupid suburban white boys that to authentically black one had to act ghetto. So now they have ghetto themed parties because they think that this is being "cool".
How did all of these folks get this image? BET compliments of this clown. He refused to play anything other than what white suburban boys wanted to here. They didn't want to hear "Fight the Power", and they cannot dance, so they didn't want to her Will Smith, or other party themed rap.
They wanted shoot em up gangsta.