Incidence
Libraries in the USA are under pressure not to stock books which can be interpreted as supporting occultism or Satanism. This includes authors, such as C S Lewis, that mention goblins, witches and the like. Such views affect the willingness of publishers to produce such books.
Counter-claim
Books of this kind are unsuitable, especially for children, because they contain fear, violence and negativism. As such they promote a sense of hopelessness and depression among children.