I disagree. Black culture after emancipation was not notably more violent, or less moral, or otherwise worse than the mainstream white majority culture. I think we're seeing two trends colliding. Our society as a whole is getting more tolerant of - even appreciative of - violence. And blacks were disproportionately affected by the ills of our welfare system which empowers women to have children out of wedlock, due to having started at a lower economic base. Remove the single parent bias and you've largely eliminated the violence and criminality gaps between races. Also remove the economic status gap (which largely goes away with the removal of the single parent bias) and the gaps pretty much vanish, depending on who does the math.
As I noted above, I don't buy into the premise that blacks inherited a slave culture, but I will say that slavery inhibits work ethic. As a slave, no one can be more oppressive than one's owner, yet a slave's hard work directly enriches that person. There is no opportunity to quit and find a better owner, the best owner is going to keep the lion's share of any surplus produced, and there is little opportunity to negotiate a better deal. (Although some slaves did negotiate a better deal and purchase their own freedom, as I understand it that is much less likely under race-based slavery than earlier versions of slavery.) Thus the South discovered that while slavery is a great way to concentrate wealth, it's a lousy way to create wealth, because it disencentizes those who produce the wealth. One can similarly make a good argument about respect for authority; if the system makes me property by virtue of birth and/or skin color, why on Earth would I have any respect for the system and its authority?
But as I said, I don't buy into the premise.
Good point.
I don't think white privilege is greatly extant anymore, but there is one way in which it definitely lingers. The legacy of slavery, Jim Crow segregation, and institutionalized discrimination left blacks statistically much lower economically. On average, if one is born black one simply stands a lower chance of being born extremely wealthy, or wealthy, or even middle class; one stands a lower chance of being a legacy at a good college, or attending a decent primary school system, or having influential friends and relatives. These things are why we have Affirmative Action in a nutshell, because otherwise the race-based advantages disappear very, very slowly.