100% just sadism. She likes hurting people, she's invented an ideology that allows her to do that without guilt.
Listen folks, if you don't give yourself permission to dress up in a leather harness and consensually whip twinks, it's going to come out somewhere else and it'll be darker.
I think it's because the abuse seen on video was largely psychological. Show her whuppin' her kids, and the cops will be there in a moment, but psychological abuse doesn't get the same attention.