The Realism of Children's Books

There was a big movement in the mid 20th century for realism among children's books. Maurice Sendak with where the wild things are who said, yeah, we're not doing that anymore. And now, well, this is more of a young adult novel, but Colin Malloy of the December is sort of three part kids' novels. I wonder though what it reflects about society at large whether it's realism or fancifulness and escapism then.