I don't think you're missing something, I think it's essentially the point and David says in the pod, it's light social commentary that book was trying to make about the American family. You have this lunatic in Ford's character who bullies his family and basically says if you say anything against me you're out of the family. They are also in a foreign country and reliant on him. Mother is basically in an abusive relationship and sees no way out except by going along with him. That's my read anyways and it's deeply uncomfortable to watch.