It could be that there's a trend in the formation of an abuser, rather than the abuse resulting from the relationship between the abuser and the victim. I've noticed that people with supervisor parents can be abusive, even to their duals.

Really though, there are too many mean assholes in the world for Socionics to explain all of them.

It's probably better to think of cruelty as a contagious thing.

https://en.m.wikipedia.org/wiki/Emotional_contagion

https://en.m.wikipedia.org/wiki/Behavioral_contagion