It happened twice and afterwards we debriefed so I could learn and understand the lesson (I'm paraphrasing you)

Yeah, that is not what we're talking about here.

We're talking about people who routinely, on a daily basis hit their children. Not hard enough to bruise, not full on beatings, but people who as part of normal daily life do things like smack their child's face or butt, grab them by the hands and lift them off the floor, push them down into seated position.

There are a LOT of people who really and honestly believe that physically bullying a toddler is a valid form of parental discipline, and would never believe that they were being abusive because they don't full on beat their children with a belt.

That's the behavior we're talking about here.