I was recently talking to someone about disfellowshiping, and we discussed the changes in policies. It seems like each time the df'ing policy was changed, there was an actual event that it followed. I'm not sure about 52, but in 74, it was Ray Franz that wrote the article and it seems like his tolerant views crept into the larger GB collective conscience. But they changed it again in 81. What happened then? It was Ray leaving.
It almost seems like the df'ing policy has it's basis in hatred. "We're gonna get you for leaving, sucker!" They needed to show Ray and the others that left Bethel how they felt. Cris Sanchez (a former spanish translator) said that he felt like the GB that were on his judical committee would have killed him if they had the chance. He even told his wife, "If they tell you that I killed myself, don't believe it." I don't think they ever would do that, but it shows the fear that they instill in others.
So yeah, I think the df'ing policy is based on FEAR and HATE.