LVEB: Most of the time they weren't. You could consider them the Saw Movies, Fifty Shades of Grey, Harry Potter, and Teletubbies of their time, all put into one genre-hodgepodge. Considering fairy tales as something for children is a rather recent phenomenon and should be seen in a similar light as "Comics are for kids" and similar statements - some of them are, some of them are not.
I beg to differ. This was clearly meant for children: it was meant to keep them of mastu... sucking their thumb, and what better way to do it than scare them shitless instead of giving them a reasoned explanation that would take two reasonable people, one giving it and one receiving it. It's like religion. How do you explain someone that he or she has to be a good person, or not steal? If he's reasonable and you're feeling like giving him a reasonable explanation, with the time and effort it would take, you could do just that. If on the contrary, you don't feel like it or don't feel like the person is worth the effort you just talk to him about "the paradise of heaven" and "eternal damnation in hell". It's been quite a headache saver.