Horror in the guise of "cute"
Roald Dahl's stories are among the darkest, most terrifying examples of the horror genre in existence. While they "reward" a so-called "good" child, they nonetheless portray depictions of abuse, including sexual abuse, extreme poverty and deprivation, and so on. They are far darker and more horrific than any "fairy tale", and the film adaptations (Gene Wilder, Johnny Depp as Willy Wonka, specifically) are even darker and more terrifying than the novels themselves. While "Chocolate Factory" is the best known of Dahl's novels, all of them, without exception, are entirely unsuitable for any child under the age of 15 or so. The books have no redeeming qualities for the age groups at which they are supposedly aimed, unless "redeeming" suddenly means nightmarish, upsetting, and terrifying.