How that idea is going to get through to someone who is somatically and / or psychologically addicted to drugs is a little difficult to comprehend. In the same vein of people will fix themselves of drug addiction is a mostly useless statement. People get into this situation either involuntarily or voluntarily, but few get out just by platitudes or sheer will power. Most people who put drug addiction behind them need a cast of people and tools to help, there is no quick fix. To be effective for anyone but the rich help needs to be available free at the point of provision. The money saved from reduction in direct and indirect crime and the increase in production will pay for the service. In most cases families see the value in reforming a drug addicted family member, why shouldn't the state? This is an effective method and motivation to solve the problem; you can reduce the demand of all of the people some of the time, you can reduce the demand of some of the people all of the time, but you can't reduce the demand of all the people all of the time; hence trying to eliminate demand is a non option to fixing the problem.
