Not sure where you got the idea that in the US people really really don't like to drink spirits socially. I'm sure it's different around the country but that's not the case anywhere I've been.
And anyway it probably has more to do with age than geography. People don't get as smashed in their late 20's as they do in high school and college when drinking is more like a competition on who can get the most drunk the fastest.
Or maybe I'm just going to the wrong parties. You're right, geography is prob a correlation.