Rap&Hip-Hop: Why are white rappers generally more linguistic?

Eminem has to fill the place of where the n-word would take place... But that's a good thing, I feel the n-word in rap songs are major fillers but could-be potentially incredible lyrics and wordplay...Atmosphere and Eminem and Aesop just have this thing about them... Eminem is not all that known for being clean but they make it work. Maybe they just want to be that great, what better way to do it with vocabulary.