Another way to post the original question is, Why are the JWs Going Backwards?
I wish I had a thoughtful answer for you, but the truth of the matter seems quite obvious and simple: JWs are going backwards because cults do not want smart, educated people in their ranks. To compare Jehovah's Witnesses with Jews (especially Jews), Catholics and Protestants is an apple 'n oranges fallacy. JWs simply are not a religion in the same sense that these are. Religions are communities of people who hold a common faith. It's not just about dogma, but about tradition, liturgy... so many things that the JWs lack. The Watchtower is a publishing/real estate company with a religious front to avoid taxes. Perhaps I am showing my youth, but I cannot remember JWs being anything more than this. If they have dumbed down the doctrine, it is only to accommodate the intellectual level of their audience