Doesn't this imply a problem with the whole "sins of the father" thing? Otherwise all of those people would have to be condemned as the offspring of a rapist.
In this case it’s especially important because those children were treated very differently from their siblings: a slave owner’s fully white children had full status in society and lived in relative luxury but those borne by slaves inherited their mother’s status. Apologists try to claim that some relationships were consensual but it’s hard to reconcile that with the treatment of any resulting children.
But then what do you propose to do about it? All of those people are dead. We can't bring them back to life and punish them.
> In this case it’s especially important because those children were treated very differently from their siblings
It was no doubt a very important distinction to the children. I wouldn't want to have to argue it was a very important distinction to modern day descendants seven generations later when that ancestor represents less than 1% of their ancestors from that many generations ago.
And the usual argument is to want to assign guilt if you benefited from a bad thing one of your ancestors did. But having existence is a pretty huge benefit, which makes that argument taste quite sour.