It poses a question of form: when a book is sort of middling, a bit boring at times but never quite bad, certainly not in any funny or remarkable way, how do you review it without affecting the same feelings in the reader of the review?
My solution: Keep it brief.
Once Upon a Time is an overview of the history of fairy tales — the major players, the major theories, the major events. From the early, sinister folktales and the men and women that recorded them, to the shift to Victorian children tales, their places in Freud and other psychoanalyst’s oeuvre, to their deep examination by 20th century feminists, and then their reclamation of darkness and adulthood in the literature and films of the present day*.
It is very general. I would call it shallow. It rarely delves. There’s a handful of interesting facts — for instance, Wilhelm Grimm ardently defended the violent lessons of fairy tales as necessary for children, while at the same time changing them to be as patronizing as possible to women and girls — but not enough to carry the book. The author is clearly passionate about the topic, but the passion does not translate to and infuse the text.
And that is easily all it takes to move a non-fiction book from engrossing and memorable to serviceable.
*I give this book points for mentioning Blancanieves, a seriously fantastic film retelling Snow White. It reimagines without diluting.