I feel that the world has taken a hard dive into "BOOKS MUST BE IMPROVING" these last few years (not just for children's books, either) and I understand where it's coming from, but I also feel that a book can only be so improving before it becomes fundamentally false about what humans are actually like, and also that if the improvement-to-delight ratio is too skewed, no one will actually be improved because the only people who will like it are the ones who have already drunk whatever Koolaid the book is selling.

It's like someone read a load of didactic Christian fiction and said "Exactly like this, but with progressive values!"