Yeah I have a mate who is into all that **** and believes that there is actual talent in it. Having spent a lot of time around him, I have unwillingly been exposed to both the music and the films. The music is always just some angry guy talking over a backing track, which is either ripped off a different song, or is really poorly made and rarely even in key. The films, as far as I could tell, are about young morons going out and getting into turf wars with other young morons, and the film makes this stuff out to be cool. It really is a stupid culture, and a total disgrace as you say.
Thankfully I think my mate has mostly grown out of it after 8 years of listening to me deconstructing and criticising it constantly. Also I imagine getting a proper job and surrounding himself with non-morons has helped. I understand that people who grow up in rough areas get caught up in this culture, but we grew up in Harpenden for Christ's sake!