It is a shame that group indulgence in alcohol is often the measure of how 'cool' someone is. More and more people are going 'straightedge'... My advice is just carry yourself with confidence -- don't shy away from your choices, own them.
I actually had to push back on our in-office boozy happy hours because a few team members were getting too drunk and it was making other people uncomfortable. My boss didn't think it'd seem "cool" if we put together a policy for how these happy hours should be handled. I don't work there anymore. :)