Discussion fiction is never dumb. If it were there wouldn't be classes devoted to the study of literature (and Harry Potter does have its own classes devoted to the study of it.)

You're entitled to your opinions, but regardless of what you want to see in literature, most good stories make it because they are relateable and believable. The psychology of characters is important to maintaining that relateablitiy and believability. Just because it's fantasy doesn't mean it shouldn't be believable.