When you think about it, when the elders disfellowship and then shun a person, it's to make an impact on the ACTIVE ones still going to the meetings, rather than the DF'd one.
They elders couldn't care less about the one who has been disfellowshipped. That person is dead to their eyes.
The reason they make this so terrible, is a warning to the ones still active, not to try this.
Some kind of blackmail, intended to the active ones.