Addicts of 'hard' drugs like heroin/meth/crack are often sufferers of abuse. Physical and sexual abuse leads to psychological trauma. When they use a drug, they feel comfort and satisfaction for perhaps even the first time in living memory. Also it finally allows their mind, albiet temporarily, escapism from the symptoms of their trauma.
Obviously this is a disastrous idea because addiction will only compound and exacerbate their issues in the long run, if it doesn't kill them. However, it's hard to see the validity in responding to this predicament by suggesting they should be incarcerated.
People like Peter Hitchens represent the view that drug addicts are not damaged vulnerable people but morally defective deserving of condemnation and incarceration. I do think we have the makings of a classic left (defend the vulnerable minority) vs right (hate the vulnerable minority) political movement here. In fact I'm surprised it's not yet being spun in that way.
Anyway, to my extreme but accurate analogy. Drug addiction is in many cases a symptom of abuse. The current drug laws punish people for what is a symptom of their abuse. It's punishing people for being abused.
Consider what happens in some theocratic Islamist societies. When a female is raped, she might be stoned to death because being raped is considered an act of adultery on her part.
This analogy may be extreme, but is it really on a completely different spectrum to what happens with the drug laws in the west?
And is the analogy really that extreme? We may not stone addicts to death, but their interaction with our 'justice' system often leads to their suicide or death because of adulterated substances or anything else for which responsibility can be laid at the feet of prohibition. We may not kill our addicts by throwing stones, but we orchestrate a system which results in their deaths nonetheless. The more vile elements in our media also propagate the view that they essentially bring this upon themselves, and deserve it. This also happens in Islamist countries with adulterers.
So there is at last some level of moral equivalency which we may have to face, even though we in the west are so good at keeping our immorality locked behind a door in a far away place where we never have to see it, or even know that it exists.
Just in case anyone wanted to ignore my argument by attaching some label to me, I might as well say I'm not a cultural relativist at all and I do regard the freedoms afforded to citizens in the west to be greater than elsewhere. Hopefully you see that this criticism remains despite that.