I am going to repeat my point as many times as necessary until it gets through: your example is only a punishment system with an extra layer to be more palatable to the society where it is inserted.
Being free does not imply in any moment an individual can do whatever they may concieve or desire; freedom requires and demands constraint, precisely because the freedom of the other is the boundary of my own. Life in society predicates on this. There is no society of one; the individual often finds a swift end if insisting on it, by its own actions.
A society that simply represses or discards individuals because they engaged in destructive behaviour is not doing anything to in fact solve a problem. A society is as responsible by its individuals as the individuals are by their society. And a society that so simply and easily opts by fractioning itself just to allow more (blatantly artificial) freedom to its elements is not a society. It is something I lack the word to describe but a society it is not.