It's interesting that people that don't like rap and hip hop and voice their opinions are "disturbing".
People have a right to be discriminating in their tastes. And before anyone goes off the deep end by the word, look it up in the dictionary.
I am a professional musician and my take on it was when rap came out decades ago, it was essentially urban poetry to a drum loop. Some of that poetry was quite good, but I had a hard time calling it music. Anyone could stand next to a running cement mixer with a steady pulse and rap to it.
When digital sampling got better some of these artists began lifting entire hooks of established music someone else created and rapped over that. Didn't get my respect at that time either. As an artist that creates music, that really turned me off to the genre in general.
I also currently work with at risk teens and many of their outgoing phone messages have their hip hop favorites playing, and most of what I hear is truly awful. The rappers cannot even rap in time to the beats on their own track.
When it comes to rebellion, many times young people will align themselves with the lowest common denominator that is sure to offend their elders. Rap and hip hop fulfills that need and you cannot get much lower than that as a form of entertainment, so it is sure to continue in popularity.
This is just my opinion as a musician. It dosen't make me a hater. We all have a right to be discriminating in our tastes, especially if we have good reasons.