I don’t dispute anything you’re saying, I just don’t understand what frame of reference any leader or policymaker at that time could have used to do anything differently. What country at that time was some paragon of social justice or progressivism? I think the US founding fathers did pretty well for their time, when most countries in the world were part of empires, or were monarchies.

People are more socially progressive now because of the passage of time, and the accumulation of sociopolitical observances it allowed. The average person now is only less of a brute because of the cultural training they’ve experienced, but it’s not something to be taken for granted.

In general, there are very few people (sages) who are more moral, ethical or curious than the average person of their own time. Often times their behavior makes them look like a loser or a weirdo to their contemporaries or society.