This is all for argument's sake, folks, I'm not trying to piss people off. (Well, maybe Jess eventually.)
Prohibition creates black markets, and that leads to crime. Sure, but that doesn't give the person in the black market moral justification. And it's the same excuse used by people who illegally dump toxic waste into streams or hide their money in offshore accounts--they'll say regulation doesn't work.
You watch your supplier execute a dozen guys with a chain saw cause one of them might work for a competitor. You then turn around and distribute it on your own terms, and pretend your hand are clean, cause you only threaten to shoot people who rip you off.
That's not extreme, that's how the trade works. At some point you have to say, how much blood is worth having a good time on Friday night?
Edit: I'm not trying compare activities, I'm trying to say you can't pretend dealing drugs is an ethical activity, as it's done today, in reality, no matter what kind of angel about it you are.