I thought that the Pied Piper was just a story, until I read this. Ptomaine-poisoned rye bread or child slavery, according to the comments… either way, it doesn’t sound like the kind of thing I’d want to tell my kids at bedtime. As a cautionary tale in daylight hours, definitely.
That reminds me of “ring around the rosey a pocket full of posey, ashes ashes we all fall down!” about the symptoms of the Black Plague. Not exactly nice fare that.
The Brothers Grimm also reworked some other fairy tales, in the original story of “Little Red Riding Hood” little red was raped by the wolf, making it even less of a thinly disguised parable about the dangers of the onset of puberty.
20th century entertainment was a lot more sheltered than you think. People bewail the amount of not-suitable for kids stuff on today’s entertainment, it actually used to be just as bad with lurid folk-tales and practices.
I looked up that “ring around the rosey” bit up a few years ago, to see if it’s true… there’s not much consensus, but the more-common opinion by those with some knowledge is that it isn’t about the Black Plague, for various reasons including when it first seems to have appeared (hundreds of years after the Black Plague burned itself out).
The general concept of protecting children from unpleasant realities is definitely a 20th (and 21st) century invention. I have mixed feelings about it myself… kids won’t always cope well with such things, but raising a child to think that the world is nothing but sweetness and light is a recipe for disaster when s/he finally learns otherwise the hard way, in a situation that s/he would have probably avoided if s/he had known the possible consequences.