I always viewed it as It's more that it's distinct from softcore porn which if you look up is more nudity and maybe simulated sex acts vs actual explicit sex acts which was accepted as hardcore porn no matter how vanilla. I'm happy to concede the meaning may have drifted as access to explicit porn became more widespreasd and softcore porn lost cultural relevance but even in that case I expect a large chunk of parents would be happier with their kids thinking rough sex is fine rather than thinking self circumcision with a rock or following voices that tell them to kill is ok.

>A thing that appears in book and stories for kids

Sure but does it appear as a moral good thing to do? If it does is it because the voice in the head is telling them to kill evil doers rather than innocents? You can see why you'd want to have a discussion with your kids about it just like you'd hopefully have a discussion about what they may see in porn not being real/healthy for most relationships. This is obviously at age appropriate times, there's a good reason kids aren't being told about Sodom and Gomorrah in all it's detail in kindergarten, why cartoons of the story of the Ark don't focus on the babies drowning as mothers struggle to swim holding them above their heads before succumbing to exhaustion or the cold... only to continue to exist forever in eternal torment.