It isn't dead, and it hasn't been. Most of those who say its dead, are those from a different era. I was born in 1980 and grew up on LL Cool J, Beasty Boys, G Rap, Rakim, etc....spent my HS years with Wu, Black Moon, Snoop, Dre, etc.....its changed exponentially over the last 30+ years and it should. The genre has grown so much, its allowed people to earn livings, and branch out into other businesses.
Its not so much the music, but its the message that has deteriorated over time. I remember an interview the RZA did years back where he stated he had no interest in school, yet he educated himself just because its what he wanted to do. Its deeper then the music. Schools are horrible, teachers don't care, young black/brown men/women have been shunned by the system for so long......its reflected in the lyrics (you can clearly hear it in the lack of vocabulary) and the message today.
Im going all over the place....but Hip-Hop music isnt the problem. In fact it has thrived for some time......the issues are deeper rooted