First, I'll say that I find this characterization of Weltman to be relevant to understanding his intended point.
Second, I'll say that Weltman seriously misunderstands children's literature. The point has been made by many famous children's writers that kids love comic gruesomeness. When J.M. Barrie wrote Peter Pan, Britain had just ended the Victorian era, when children's literature was serious, morally upright, and deadly dull. Peter Pan upended that and became a smash hit, possibly even bigger than Harry Potter has been.
Second, I'll say that Weltman seriously misunderstands children's literature. The point has been made by many famous children's writers that kids love comic gruesomeness. When J.M. Barrie wrote Peter Pan, Britain had just ended the Victorian era, when children's literature was serious, morally upright, and deadly dull. Peter Pan upended that and became a smash hit, possibly even bigger than Harry Potter has been.