As. Mexican, I agree with you. The conquistadores weren’t people of the highest caliber, and while the catholic monks were better, their mission was evangelizing at any cost, even if it meant killing people who didn’t want to. Even prehispanic people could be brutal.

The main difference between colonial Mexico and USA was that slavery wasn’t a thing here, because the evangelized became full-fledged catholics, having a would and all. Something unthinkable for the slavers, who justified their acts because blacks “didn’t have souls”.

Mexican creoles, the hacendados, found a loophole: Catholics could still be exploited by crushing, multigenerational debt. That’s why we had a century of turmoil after the revolution(s), right after the century of turmoil after our independence from Spain.

Guess my point is: by the time USA invaded and forcefully took half our country, we didn’t have slavers (the hacendado’s loophole was gone), and definitely didn’t trade humans as things.