In my view your dismissal of 1950's whites against interracial marriage as "bigoted assholes" is itself a bit of presentist bigoted-asshole-ism. If our approach to people in the past who held opinions we find detestable is to condemn them, how are we supposed to deal reasonably with people in our present who hold similarly detestable opinions? Is everyone who disagrees with you just a bigoted asshole? Is there no possible way to see such people as responding reasonably to the information they have, the situation they're in, and the pressures they're subject to?

Sorry, I know it's not really relevant to the article. I just don't like the sense that everyone in the past who was racist or anyone in the present who's sexist or whateverist is just worthless garbage, or "bigoted assholes". People are more complicated than that. People holding opinions you hate can nevertheless be moral relative to their cultural environment, given the thoughts that made sense in their milieu.

Forecasting the development of moral judgments decades or centuries before it happens and living according to that future standard is an impossible and pointless task. People should be judged according to the times they lived in, not according to our privileged, 20/20-hindsight present moment.