It's all just willful and petty ignorance. Some also threaten to disown a child over an interracial marriage. Lots of people will disown you over that to this day. In the 1980s, my own father said "no daughter of mine is going to date a damed sand n**ger" and "she'd be better dead" about the possibility of me ending up in a mixed race relationship.

TBF, within a decade, father gave more respect to my Persian husband than his other three sons-in-law. Full disclosure: I didn't marry until I was twenty-eight and am inclined to believe the scuttlebutt that my parents were just glad Hamid is a man. 🙄