What I've always been wondering about (no sarcasm) is if there was no "bad" hip hop, would there be neither ghettos nor violence nor bad attitude nor condescending behaviour towards women, authority and other institutions?
Admittingly, the proper question would be: Would there be less of these things and what is the trend? I'd really like to see some studies of this. I don't know about American ghettos but in certain parts of Germany rock, skinheads and xenophobic behaviour go hand in hand.
Certainly, the media has its influence but the question is whether the development and behaviour of hip hop is dynamic or static, that is whether it is willingly imposed by somebody (MTV, Bad Boy Records, etc.) or whether the people choose it hence increasing the output thereof. In today's time where the available options in music are truly rich, you don't have to listen to hip hop if you don't want to and that goes for the people living in poorer areas, too. Sure, peer pressure can be strong but is everybody just deceiving themselves then? I don't have much data on this issue but I like to think that a thorough analysis can be quite complex.
Without drawing a conclusion of whether hip hop as a form of music isn't simply instrumentalized or whether it doesn't indeed have its bad influences, I'm pretty much convinced that the real problems lie elsewhere, that is welfare, social standing, income, etc. It certainly is not a clear-cut case where hip hop is to blame. Even assuming hip hop does bad, I think it would be hindering to prioritize the battle against hip hop too strongly because it distracts from the real issues and creates an atmosphere of distrust on top of that. I'd be quite confused, irritated or even angry if people were to denounce my behaviour but critisize jazz and classical music for it.
So in my opinion saying that hip hop is the root of evil is kind of dangerous because it does neither adress nor does it solve the real problems in any way. Rather, it polarizes the conflicting sides on issues that don't touch the core.