The whole idea of reinstatement stinks to high heaven of "men playing God." It also goes 100% against the instruction from Jesus to "stop judging."
Christians believe that God forgives sin based on the blood shed by Jesus. The Watchtower believes that three elders forgive sin based on whether they "feel" like a person is repentant.
All sorts of prejudicial feelings then comes into play - if the elders have a personal agenda against a certain type of sinning, if they know of past sins, or if they are just power hungry and want to use their position to "make someone pay".
DFing used to work, at least sort of. They could blackmail people back in just to get their family, and many who were DFd actually thought it was the "truth". Now, everytime they DF someone, they risk that person coming here or jwfacts.com or any other site and freeing themself mentally. Once they do that, there is little to no chance they will ever return. If so, it will be only for family and they will quickly fade if possible.
Now that the internet has exposed them, the DFing policy is truly counterproductive. It will result in net losses in the long run.