It isn't my position or responsibility to prove you wrong, I'm just providing another point of view.
First things first, i DID misread your original post, and implied that you said gangsta rapping was a *cause* of today's ills, when you actually said it was a symptom.
That said, you still support it being eradicated, as a "bad" influence. Which, although it isn't a part of the constitution of Australia, is still a treasured value if not a right here, and in most if not all the democratic nations of the world. And barring a particular genre of music strikes at the very heart of these values.
In short, you suggest getting rid of what you believe are the symptoms of a failing society. But neither you or I are in a position to judge what is good or bad, and we shouldn't contravene other people's rights to impose our own view of good or bad.
Even if they swear in the music.