Your exact quote : "rap music is going to go down as the single most important thing in history to hold black people back"
You didn't say it's what's holding black people back here and now the most. You said I'm history. If you think rap music about sex is more detrimental to a community than 100+ years of being hung in trees, having communities burned down, not having access to proper schooling and or decent jobs, not being allowed to live in nicer areas, the list goes on and on and on. Then you are completely ignorant.
This isn't something that happened generations ago. Most black people alive today lived through at least some of these things, experienced them first hand. And if they didn't experience them first hand almost certainly their parents and/or grandparents did.
There are literally people still alive today they had parents that were slaves.