Quote - But if there's some cultural context here I'm missing, I'd like to know what it is.

I'm not sure if it is a cultural thing, to be honest.  From an author's perspective, I'm not sure their motivation from an artistic perspective is any different than some of the ways I've killed off my plucky bit characters - "You know, it would be fun to ...".

 I mean, I'm pretty sure most of the people here would skip the 3/4 page description of how one of them feels and dies after having a form of liquid thermite injected into their vein - but at the same time, that scene is one of the more popular ones I've come up with.

At the end of the day, whatever the motivations for creating the artwork, it might just boil down to "there's a market for it".  I don't know if anyone's done research into the motivations of that market, and if there's any connection between it and child abuse in "real life".

It also raises a question - should artists be held responsible for what people do because of the art they create?  That's a really risky extension of responsibility.