Yeah, no. Heroin and tobacco are products, and I am in agreement that products with crappy value propositions and high margins are unethical. But I don't know why you chose those extremes. They paint a false dichotomy of the danger inherent to liberty of consumption.

If we have to use extreme analogies, I would rather use prostitution, because it is a service. Just like Dollar Shave Club, I think there is legitimate customer demand and it shouldn't be illegal. I also am not going to judge someone for partaking of it even though there exist easier or cheaper options for getting the product - sex. So that just brings us full circle to my original point, which appears to still stand.