Yes, I said that. Nowhere in that did I say "consider the atrocities", because that's not what I was talking about. If I was, I would've said so.
All things being considered, the nature of the event, the event itself, time and the change in sentiments, etc... people will continue to disapprove of atrocities/crimes against humanity the more time goes on.
Imagine carefully planning to murder someone, and successfully carrying out your plan. Now imagine someone has broken into your home and threatened you, and you killed them in self-defense. Now multiply this by millions.