I think that the guides and the schools are looking at the lowest level, not even the average

I think that's the point. It's set up to be inclusive, and to look out for those at the lowest level since those above it can manage better. I'd like to think the guidelines were born from kindness, and is just mishandled afterwards. As for Violence vs nudity, I think it's how it is handled and its effects. We have the police for violence, but nudity can lead to sex and early pregnancies which can wreck children's futures.

I wonder if you (and I and others) learned better lessons in life because of this kind of exposure

I'd like to think so. As they say, what doesn't kill you makes you stronger. Of course, it all depends on how we cultivate that experience. Criminals chose the wrong lessons to learn from those experiences.