Fairy tales educate/corrupt

Once upon a time there was the world without fairy tales. And people of this world were cruel and evil, because they didn't know what the love was. And people from the world died out. This is the brief plot of what is going to happen if all fairy tales disappear. So, what is the role of fairy tales in the education and development of children?
People consider that all fairy tales have the educative purpose. And as little children grasp the world through bright pictures and images, fairy tales educate them providing with certain moral and ethic education.
Nowadays there are so many fairy tales and some of them are not so good and kind. Even well known story of Peter Pan depicted the world of dead children and not the fantastic world of kids. And remember all fairy tales, almost in all fairy tales the enemies of main characters are killed violently by the main heroes but in the end everybody is happy. Remember the story of Carlson who taught the kid not to obey the baby-sitter. And all these fairy-tales are read by children.
So can these even classical not to mention modern fairy tales educate our children and form good and kind creatures?
The modern fairy-tales and cartoons are not better. If the images of old cartoons and fairy-tales were beautiful and well-created, the modern cartoons depict the ugly images created by computers.
So maybe it is necessary to prohibit your children to watch these cartoons and to read fairy-tales?