What jumped out immediately at me about these "fairy tales" is that the ones written by Oates and Jewett were so much less of what I would consider a fairy tale than the others.  The basic plot in Jewett's "A White Heron" is a girl meeting a bird watcher who wants her to take him to the white heron.  There's nothing supernatural about that at all.  In Oates "Where Are You Going Where Have You Been?" a young girl is attacked and murdered by a crazy man, but again no supernatural occurences.  In "Little Red Cap" both child and grandmother survive by being swallowd whole by a wolf, Cinderella has enchanted birds and trees that drop down beautiful dresses, "The Little Mermaid" has magic sea witches and "In The Company of Wolves" werewolves.  All of these are supernatural or non believable occurences, which to me is what qualifies them as truly fairy tale.         Obviously in the Disney remakes of "The Little Mermaid" and "Cinderella" things had to be changed in order to reach the target audience of young children.  If these fairy tale beauties didn't win the hearts and hands in marriage of their princes then the whole notion of living "happily ever after" would be thrown out of the window.  It's also a money making scheme.  No parent is going to buy a movie for their small child where girls are cutting off body parts to fit into a shoe or another gir losing her prince to someone else and essentially dying.  Although these may portray a more realistic ending to an unrealistic situation, in this case realism doesn't sell.