When I was an addict it was my choice entirely. No-one else's fault at all, just mine. What you are proposing is to take people's personal responsibility away from them and let them say "oh yeah I'm a drug addict , it's not my fault, I'm a victim". THAT really doesn't help. Yeah you are a victim, you are your own victim, and until addicts understand that they stay addicted.Plus a lot of low end dealers are the most pathetic of addicts who are bullied into it by other people who cream off the majority of the profits or who only do it to fund their own addiction and to avoid mugging people etc.
People need to be brought up as valued, worth something and with the expectation that they will be a valued member of society, THEN they are less likely to have the hole inside them that drug addicts feel they need to fill with drugs.