Both of those arguing understand that people of the given time work within the understanding of that time

Hmm. The "of his time" excuse is a popular fallback. It was OK to be a bit of a racist in the 50s and 60s and make Paki jokes because we were "of our time". Well it don't wash with me. The best people of this or any other time were independent of mind and were well able to think outside the box, and, if they were bold enough, to speak outside the box. Now the speaking was the hard bit, but the thinking - well, there's no excuse for racism, for example, or, shall we mention homophobia, or mysogyny, either now or way back then. In either case you are losing love for your fellow humans. Plus ca change and all that, as people such as Richard Dawkins and Hitchens, the ones bold enough to speak outside the box, against the tide, who challenge received wisdom, are the ones most vilified today, just as they always have been throughout history. "If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away..."