I'm all for living and let live for people don't harm others, whether they're addicted to drugs or not.
I think most addicts are also casualties of the drug war. If the government supplied clean drugs with very little markup from the production costs, and intervened for users who harmed others (using some combination of imprisonment, forced rehab, and counseling) I think we'd be much better off.
Add to that, drugs could be both cheaper than current street prices (less motivation for things like theft), on top of being a source of revenue to fund the social programs