I think it's more the labels pushing the goofiest, wack nikkas from the South and almost no one else. The South themselves didn't help, though. Between little to no Hip-Hop culture being popular (little or most likely no scratching, beat boxing, graffiti or Hip-Hop dance in the videos, or reverence for the culture/pioneers), and them making it cool to be wack at rapping (the crying over Nas' HHID album was mostly "not everyone is nice", or "nikkas wanna talk about partying and bytches" which was a lot of them telling on themselves). They got the top spot and abandoned the culture for strippers, tricking and ignorance. Eventually, even the southern rappers that had Hip-Hop culture in them went away. NY put the nail in their own coffin by following and trying to sound like that trash and watering down the sound. Now, they have a whole generation of kids who basically aren't New Yorkers, artistically.
No excuses for an alleged GOAT who got an old song with the rhymes already on there.