Re-think the comparison I gave. The point I was making is the fact some people can keep things under control and suffer no ill effects does not change the fact it's an addictive substance whose consumption leads to ill effect.
While you do caveat things in your second comment, both your original and second comment basically minimize the OPs "not even one" stance, even calling it "nonsense". Replacing everything you say with alcohol shows the disconnect; you wouldn't say similar things to an alcoholic who said "alcohol makes you intoxicated", saying that's nonsense (since there are plenty of substances that can make you intoxicated) and then proceed to tell them that one drink is fine.
It's like saying an alcoholic can still responsibly drink by stopping at one.