We both agree Rich white people listening to gangster rap is ridiculous. However, I think we both agreed as well there's not many that do so.
I don't see how there's anything else to discuss if that's the case.
What it sounds like though is you're trying to argue that it's ridiculous for rich white people to listen to any kind of rap, hip-hop, or R&B. Based on your admission that you don't know anything about rap then I'd wager you should listen to some of it before you make judgments on who should and should not listen to it. If you're sincerely interested in your question, of trying to understand why others listen to rap, then you'll view that statement as encouragement. If you're not sincere then you'd see it as an attack. Either way I don't care.