Don't be silly. They have to get drugs from somewhere. Unless you propose to put them in supermarkets, there's going to still be people thinking they can sell tablets which have god-knows-what in to people who don't know any better. What about the poor person's family? It's a totally selfish argument to say you have the right to destroy yourself, because it's not just about you.
You might like Artaud:
It is not opium which makes me work but its absence, and in order for me to feel its absence it must from time to time be present.
Antonin Artaud

