A century ago, opium dens were popular in every large American, Asian, and European city. Those whose disappointments with life brought them to a state of depression would frequent opium dens until they ran out of money. Then, they died.
Opium users sought stupor instead of violence. Their lives did go downhill when they continued to satisfy their addiction, but they only hurt themselves and their families. Neighborhood opium dens accelerated the process by which the doomed disappeared. By getting themselves out of the way more quickly, their families could make faster recoveries.
Did big-city politicians in the 1800s encourage opium dens to be built in their most crime-ridden neighborhoods? If so, what were the downsides? If the damage done by few thousand angry, bitter, violent people could be eliminated by a few pennies worth of opiates, what was the harm in opium dens?
A crime-plagued city like Philadelphia could experiment. Modern chemistry has reduced a dose of opiates to a few pennies. For a few thousand dollars, Philadelphia could re-open virtually free opium dens in violent neighborhoods. Lives and property would immediately be made safer. Millions of urban residents could enjoy life without threats of violence.
The addicts, as well, would certainly have a more pleasant time.