I thought by thanksgiving dinner, the real Norman was also already turning into the goblin. He was using his evil voice. By the end of the film, he could turn sympathetic Norman on and off to suit him. Norman was overbearing checking Harry's house twice a week, it's true. But he was shown as mostly kind and thoughtful. The text of this film is rich and there's a lot going on, but the greedy green goblin businessman is definitely a moral.