Another side of this, is that if you buy/drink sugary beverages a lot outside of those social situations, you're also likely to get criticized about this. Every other peer tries to remind how unhealthy coke is, how one can clean rust with it and so on. And this is not out of health concerns, but just the same case of social situation conformance stereotypes - one's expected to drink while partying, but don't they dare to do the same alone at home.