Offred is nailing it in my opinion - we recently listened to it in the car, and I had forgotten all the stereotyped side comments (like Blyton in the faraway tree) - but it still rings out - Matilda is the hero, it's about the child, and the exaggerated adults are all from a child's black and white view (I also agree about the passivity of Miss Honey, and Matilda being the one with the strength which inspires her to actually do something)
James and the Giant peach is the same, hell, Charlie and the chocolate factory - it's all a child hero, and the world viewed through that child's eyes.