Heroin is a mid to upper class drug
Is everyone in the supply chain mid-to-upper class? Is the guy doing time for importing it?
The answer could be "yes" - I don't know enough to say with much confidence - but my point is that you seem to be talking about users while parent seemed to be talking about supplier and those are two very different questions with potentially very different answers.
Lots of money importing heroin, due to the huge black market created by the criminalization of supply and possession. You know for a fact the guy that got locked up for it got immediately replaced by the next schmuck whose opportunities in this supply chain dramatically eclipse anything he'd be able to attain in his economically devastated, capital-starved community.
We created the ghettos, we created the economic incentives that cause good people to make bad choices. http://www.thedailybeast.com/articles/2014/03/13/how-we-buil...