Is it possible that their behavior just sticks out to you because they are Mormon. By that I mean they actually aren't that different, but because you are sensitive to their being Mormon it makes it seem that they are snobby? Just a thought. Also, in this situation alcohol isn't the only factor. We Mormons place a high priority on family and they might not want to cut into family time or perhaps they feel like the conversation would make them uncomfortable. I don't disagree that we can be difficult to work with, but we also don't just expect you to make all the concessions.

Finally, I have a brother-in-law who is a doctor, and he hates out of town conferences because his colleagues just go and get drunk and waste their time. So it's possible that that is what they have just come to expect, even if it isn't what actually happens in your group.