We have people who are serving life sentences in prison. That is functionally deeming someone unfit to rejoin society. This kind of judgment is already being passed on people, we just don't have the balls to be humane and kill them.

I readily give you your point that people would abuse this to persecute their enemies. The fact that our society is so divided takes many solutions off the table, as they only function in a more cohesive society. Instead we're just gonna careen down the road to anarchy and/or tyranny because the populace is divided against itself.