In no way did the Justice system rehabilitate me. Besides the fact that I was in possession of a plant, not electrocuting the deer and beating them to death when they ate it.
Hmm... now you've got me wondering if weed-laced deer works as well as weed-based brownies.
Granted, possession is not anywhere as heinous a crime as killing or maiming any living thing. That said, it's not uncommon knowledge that many people convicted of murder do not think their crime is/was as heinous as, say, rape. I think most of society has somewhat of a "sliding scale" when it comes to the immorality of a crime. There are others who would seem to want to throw anyone committing a crime under the jail, however.
But the point I was making in responding to you to begin with was about whether rehabilitation was possible... or not, because of a prison sentence. I've seen it happen. The person has to want that change, however.