i dont think its a direct cause, but its a factor. back in the day, the things the real dudes did were mostly secrets. it was whispers among people in that area but nobody said it out loud and things were sort of taboo. rap put the shyt out on front street and even glorified it. before the goal was never to make your name ring bells, it was just something u had to do to survive and u kept your mouth quiet about it. but because of rap, everybody has to know your dirt.
i guess its not so much the violent nature of rap that i find to be so bad for the youth, but the braggadocio of it. it makes it so some of these kids are HOPING for a chance to prove themselves and make their name ring bells. not like the rappers they listen to, but the real street dudes who the rappers glorify.
I think you have to go way back in the days to find a time d-boys and street nikkas weren't deified in the slums, it was happening during the disco and funk era, the music just wasn't conveying it so people think it wasn't.
And it's not even exclusive to the USA, you can go to Africa or South America and the slum kids look up to and want to be the like hoods that run their slums, it's kinda goes back to speech at the beginning of "Goodfellas" kids wanna be gangsters because they seem to have power in an area where nobody has power.
People forget white folks were deifying the Mafia and dudes like Capone and the Commission long before black crime made it's way into entertainment.
Alpo and Rich Porter were those nikkas in their hood way before the era of gangsta rap, same goes for Preme Team, Frank Matthews, Frank Lucas, all those legendary new york drug dealers. Or gangsters like Raymond and Tookie, Larry Hoover, Jeff Fort etc.
But you have a point with the rappers helping to bolster the street nikkas legends and glorifying it, like when Drake comes to Houston he is with killers from all sides of town smiling, calling them his brothers, popping bottles in V-Live and Limelight.
There are kids that probably see stuff like that and consider meeting celebrities and being "live" as part of the benefits of the street life and think "hey I can't rap or play sports, but if I earn a name in the streets I can be a somebody too".