Very little at the state and especially Federal level these days is as simple as "right and wrong". You hit the nail right on the head.
The WOD is a "growth industry. Then there are all the extra Judges, Probation/Parole Officers, Court Clerks, Public Defenders, Paid Lawyers who profit(are employed because of this WOD) therefrom.
Then there are all the additional prisons which have been/are being built, as well as all the Corrections Officers, Admin. Staff, Counselors, outside vendors, contractors, etc., who benefit from this situation.
We now imprison more people than ANY other country IN THE WORLD and at least half, are for drug related offenses, and of those, most are for mere possession.
Insanity.
Of course as Sittin Yonder has suggested, what we really should do is simply execute them all, and then we would not have to worry about prison overpopulation problems.
20% are there for drug related offenses (and 75% of those are black or Hispanic), and almost all of those are for trafficking or drug dealing. Very few are there for possession, and I would guess those cases were plea-bargained down from dealing.
It is interesting that we have such a bad drug out there (nicotine), legally being used and taxed and yet we can't even consider that possible approach for the drugs that make many people a living on both sides of the trenches.
I am also not sure I have a real comment about putting all "users" to death that would enhance the discussion.