I also have compassion, and come from (and live in) a country with pretty hardcore drinking culture.

And yet even the "fun uncle" himself knows how bad it is. Before the family gathers and drinks vodka like there is no tomorrow, everyone is aware that it's poison, what they will feel tomorrow, that someone will need to take care of then uncle somehow, and nobody is really even pretending that it's just fun and harmless.

Ultimately it's all about making conscious decisions or not. One could argue, maybe, that inability to make good decisions in obvious situations is the real disease, but it's not really a thing in our culture - or maybe it's actually the same thing you mentioned with chemicals: once you make the stupid decision to drink, vodka is also being used as an explanation for other stupid decisions, making it harder to see one's weaknesses? Not sure.