Um, I guess I have an ethical problem of just "washing my hands" of something that is killing a thousand young people around Vancouver every year, regardless of the degree to which their own decision making is pivotal to said death rates.

Humans have created agents that kill, including cigarettes and vodka and heroin and handguns. True, i am not the inventor of those agents, but as a human, I kind of like the idea of trying to reduce the degree to which those agents slaughter my fellow humans, regardless of the degree to which free will as a component of their interactions with said agents.

Your way of thinking would never have led to seat-belts and airbags in cars and would never have led to bicycle helmets for children and would never have led to Mothers Against Drunk Drivers. It would have said, bah, humbug, let them all die, they are making their own stupid choices, why should others in society waste their time trying to improve the situation.