This is the main point. Because it's "free" you feel like you need to avail yourself of it.
Probably true. I never drink in US lounges that don't have an open bar, but instead a barkeeper that I would probably have to tip.
At the same time, the reason I do enjoy lounge and on-board drinking is because it's one of the rare occasions I can get anything done for work without having to be sober. Even if it's just getting from A to B
