Why would that be the assumption? If Black history is the reason for the disparity between white and black people (in the US, presumably), why can't the history

Why would that be the assumption? If Black history is the reason for the disparity between white and black people (in the US, presumably), why can't the history of treating women as delicate quasi-children without agency be the reason for the disparity between women and men? Or perhaps the history of mass sacrificing men as expendable soldiers? Or any other past or present practice that no doubt has an effect on current cultural norms?