Drugs drug dealers sell don't have a benefits and hurt people. Most crime in cities is through drug dealers or is drug related. Doctors give you medicine and they are supposed to check you to see if you will be susceptible to side effects the medical drug may have.
A drug deal isn't a doctor. Don't fool yourself into thinking they are good people.
Drugs have the potential to hurt people, just like cars and cheeseburgers and peanuts. It's silly to compare a legal system that is highly regulated to another system that is unregulated precisely because it's illegal. Besides, we have legal drugs that claim far more lives than illegal drugs, but you don't often see campaigns looking to run the local liquor store owner out of town.
EDIT:
Sorry, missed Hungry Donner's post...
...what about discussions on cannibalism? Are those kosher? Those guys seem to get the cold shoulder plenty.