How many people has he killed with his drugs? How many people have been robbed or burgled, car-jacked, etc. to raise money to buy his drugs?
Those crimes are no more on him than they are on the drug prohibition and the DEA. How many fewer ODs would there be if the drugs were of known purity, not coming from the criminal element, and how many fewer robberies and carjackings would there have been, if the drugs were sold at only modestly above the cost of production, i.e. in a free-market marketplace?