Why don't black Americans ociate with their Bantu roots?

Instead of trying to claim Nubians who were Nilo-Saharan, the Tamarians (ancient Egyptians) who were Cushitic, and other indigenous Africans? How come they call themselves Bantus but they will proudly refer to themselves as "Nubians" and "Pharohs"? Did you know Bantus were used as slaves across all of Africa and were said to have the lowest IQ of all African sub-groups? The Nubians specialized in trade and business while the Cush specialized in architect and chemistry or "alchemy". Do you know what Bantus were? Farmers and slaves, and in there own west Africa they were lawless savages that use to brutalize and pillage each other. So are black Americans ashamed of this?