Why judge folks for what their ancestors did in the past when folks do enough on their own today to sufficiently condemn them?

Two adages come to mind. You can't have too much of a bad thing, and, pile on the agony.  

Well speaking as someone who has faced more than a few rather ill-informed comments about my countrymen's ancestors I say we should not judge current generations by the actions of their predecessors.. In my case my ancestors would have been poor people,with no say and little more than slaves themselves - hardly in a position to influence anything