Frenchy,
What you say is right but you're not seeing the problem as JWs do. For them, a person who is out of the religion has no chances of surviving Armaggedon. So what they try to accomplish by shunning is not to show their disapproval on the person's lifestyle but to psychologically
coerce the person to go back to the Org. They really think it's the best thing to do, and it's something that fits perfectly with JW mindset. I don't see how this could change, unless they drop their claim of being the only true religion (something unlikely to happen in the foreseeable future).
JJ