> It's even hard to understand it because we were not involved in the slave trade. And we really can't understand what problems experienced and continue to experience black people in the USA. This is true, but while it is hard to understand, it's much more easier to understand that making them play main roles in historical movies doesn't repair any injustices made to them.
It (and this is usually fiction in historical settings, not historical movies, which are different genres, unless you are talking about black people playing black historical figures, which is a weird thing to object to) repairs (or, more accurately, mitigates) the injustice of current, active discrimination and underrepresentation of blacks in the film industry, not some distant historical injustice more closely tied to the slave trade.
It (and this is usually fiction in historical settings, not historical movies, which are different genres, unless you are talking about black people playing black historical figures, which is a weird thing to object to) repairs (or, more accurately, mitigates) the injustice of current, active discrimination and underrepresentation of blacks in the film industry, not some distant historical injustice more closely tied to the slave trade.