One important point is that Asian immigrants remained culturally intact (except for immediate family members who joined them later). Their language and cultural traditions were not destroyed. Assimilation was gradual. Although social and working conditions were harsh, they were allowed to live amongst each other and continued to educate themselves.

Africans were stripped of their languages, their families, their traditions and their religion. They were, in fact, subjected to cultural genocide. They were not allowed access to education in any form and even after they were freed, barriers were erected.

I think the operative word is cultural genocide.