I'm not sure I agree with this ruling. If a person is receiving the same exact pay and benefits of those co-workers which are in the union, then that person should pay the same union dues. If he is not receiving the same pay and benefits, then that's a different story.
This ruling would be akin to me saying I don't like what the government does with my tax dollars, so I should not have to pay taxes. I live in a very democratic county in a very republican state, Indiana. If someone in this county were to feel that they weren't getting what they considered proper representation by the state, why should they have to pay state taxes?