Firstly, substances can be used without 'abuse'. Alcohol is a good example of this, you probably know many users who never abuse it. Alcohol most certainly can cause severe, immediate harm to the abuser an society.
Why ban substances based on harm? Why not just enforce the rules around the actual harm?
For example, enforce driving under the influence and don't ban alcohol.
Is there really a need to ban things like heroin which have a high rate of causing harm to the user? It seems like it is more of social and community issue. Throwing that person in jail is hardly improving their life.
Managing harm, as you suggest, is the best way to handle things going forward. It also covers a lot of things beyond drugs, things that are addictive for some people like gambling.
In terms of priorities it should be avoiding harm to others, such as not driving under the influence as you suggest, and then avoiding harm to the individual, as might be the case with a chronic alcoholic.
As a note, heroin isn't as inherently harmful as it's made out to be, but, like other things, so long as it's illegal it will really only be popular with the more hard-core drug users. It was legal before, after all.
Firstly, substances can be used without 'abuse'. Alcohol is a good example of this, you probably know many users who never abuse it. Alcohol most certainly can cause severe, immediate harm to the abuser an society.
Why ban substances based on harm? Why not just enforce the rules around the actual harm?
For example, enforce driving under the influence and don't ban alcohol.
Is there really a need to ban things like heroin which have a high rate of causing harm to the user? It seems like it is more of social and community issue. Throwing that person in jail is hardly improving their life.