Seeing something you think is culturally wrong is not necessarily traumatizing, is it? And surely there are degrees of "wrongness", ranging from the merely uncomfortable to the truly gross to the utterly horrifying. Even within the horrifying category, one can differentiate between things like a finger being chopped off and e.g. disembowelment. It's reasonable to expect a person would be more traumatized the further up the ladder of horror they're forced to look.

This would be believable if not for the fact that hanging gutting and quartering was considered good wholesome family entertainment to watch while getting fast food in the market not three centuries ago literally everywhere.

How did that go away, if people only do what they're brought up to do?

We found out that keeping people homeless to die of exposure slowly was much more effective at keeping the majority in line.

No one is actively trying to keep people homeless or watch them die on the streets, much less use that as a lesson to keep people in line. Drawing and quartering is way more scary and effective if you want to make people obey. You're just mixing nihilistic bitterness with outright nonsense.

Depends seriously on the country, the Netherlands was way ahead there. In many ways more ahead than it is now because it has become so conservative lately.