There's always a motive with JWs. They shun people to get them to return to the fold. They are nice to non-jws so that they might recruit them. They are kind to other JWs so that they won't stumble them and be blood guilty.
They are never just genuinely loving and kind because they have a deep rooted conviction that that is the way you should act- regardless if the person on the other end is a jw or gives you anything in return. I would call that very selfish.