The suppliers of product to the existing market all being gang members is a largely boomer myth that has not helped the image of cannabis.
What is more dangerous is professional psychiatrists taking results of past studies on cannabis and its links to psychosis out of context. Studies have shown there is a link between cannabis and certain mental illnesses, for instance schizophrenia but these studies typically do not go as far as to explain causation (unless they have an agenda bias).
The point is, the studies do not go as far as explaining that there is a real possibility that sufferers of mental health illnesses are seeking out cannabinoids as to decrease symptoms of their illness.
The NZ psychiatrists are doing their industry and New Zealanders a disservice by not doing more research themselves and simply giving in to reefer madness.