Because we don't enforce it. Suddenly it makes perfect sense why Australia was used as a penal colony way back when. I wish we had a huge island that we could ship all these cretins to so they could fend for themselves and not be able to harm civilized society not cost society anything.
I would be for this also, IF they are truly guilty and get the same chance to prove innocence or guilt as everyone. However I am not so sure about sending a seven year old to a penal colony.