I've always taken them as child-friendly introductions to the idea that life is sometimes hard, and that bad things can happen to good people. I suspect, though

I've always taken them as child-friendly introductions to the idea that life is sometimes hard, and that bad things can happen to good people. I suspect, though I don't know, that children of Grimm's era were obliged to play a part in society far earlier than they are today, making such lessons quite valuable. (The idea of preserving innocence is relatively new).