There has long seemed to be a curse over Africa, but it doesn’t have anything to do with Nephilim who all got drowned in the Flood. Voodoo, witchcraft, and hate go together like a horse team and carriage. It wouldn’t matter if they looked like green Martians, the result would be the same. This made it particularly easy for slave traders, they’d just pull up their ships and ask what tribe the folks living near the shore hated the guts of, then said lucky you, we will take them off your hands.
Okay, but even in civilized countries black culture the majority act like savages.
Which invalidates your explanation...it could be argued.