To mark Roald Dahl Day (his 100th birthday), which fell on Wednesday, Michael Rosen wrote for The Big Issue about the peculiar thrill and excitement that inevitably followed the revelation that there was a new Dahl book on the way.
On the surface, his books seemed to break all the supposed rules for children's fiction. As Rosen notes, they were "outrageous", studded with grotesque and scheming characters, and incidents that "were so extraordinary or odd that we would perhaps wonder how he had got away with putting it in a book for children". Moreover, while there was undoubtedly a moral element to some or even most of the stories (the good ending happily and the bad unhappily, essentially), there was apparently little room for reform and redemption.
And yet despite these elements - or, more likely, because of them - his books were phenomenally popular with kids. It must have been enough to give many a conservative educator a headache.
(Thanks to Lucy for the link.)