I keep seeing Very Smart People stating in an authoritative tone that Watership Down was ~obviously~ not a children's book and it is very annoying to me that people will make that assertion so confidently while either not having bothered to read anything about the book itself or else just leaving out the inconvenient fact that the author himself would disagree.
I think about how as a ten year old, which was around when I first read Watership Down I had already read large narrative chunks of the Bible. Since I was four years old, I had heard a story about a child killing a man with a rock and cutting his head off to show off to people and another story about a man being tortured for days and...
like, Watership Down was fucked up and dark but I think the thing that makes people balk at it is the idea that they don't expect it to be challenging.
There's this quote from Chesterton, something to the effect of 'the child doesn't need the fairy story to teach them about dragons; they know the dragon since the first time you turn off the light. But the fairy story tells them of the knight that knows how to slay dragons.' And I think about that a lot when I think about the horror in kids' stories that people recoil from
There's this anecdote Neil Gaiman tells in interviews, that Coraline was almost not published because it was too dark and scary for kids. But then someone's child read the manuscript and loved it, so they ended up publishing it
And Gaiman's reasoning for this is that when adults read Coraline, they see a child in danger. But when children read it, they see a child get out of danger.