I partially agree with what you say, ernest, but disagree as well. Saying heroin turns someone into a criminal 'other than the need to procure it' is kind of like saying war isn't so bad other than all the killing. The crime almost invariably committed to support a heroin habit is the root of the problem. Also, all the available treatment in the world isn't going to dissuade a user who doesn't see sufficient consequences from their drug abuse to quit. The threat of incarceration and/or temporary incarceration often is the 'hitting bottom' necessary for an addict to want to make that change.
Simply put, there has to be a carrot as well as a stick to combat drug addiction.
Why would a heroin addict commit crime to get access to a drug that is provided to him through the public health system?
The cost to society of forcibly providing dissuasion is in most cases greater than providing a managed level of the addictive substance. You're still approaching it from the viewpoint that addiction in itself is a moral failing and therefore society must correct them sternly because of that, no matter how much harm society itself suffers from applying that correction.