The devils advocate here is when you decriminalize all drugs, like some states have done with weed, is you remove the black market income from the oppressed and put it legally in the hands of those that have the capital to start a business and run a legal dispensary. We just sent out an $800K quote just for millwork in a new dispensary in Santa Ana. The local corner dealer will lose significant income from the suburbia crowd that come into the downtown areas to buy. Those "respectable" folks will go to the "drug" stores. Crime will increase in other areas to make up lost illegal income.
On the other hand, there will be better control over "bad" drugs. You just gotta decide which battle is hte most sensible to fight.