As a brother who fits that description I wouldn't say I think I'm better than anybody but what I will say is in my opinion, people who don't smoke , drink , etc usually are the types who have a mind of their own and don't care about fitting in with the "cool" crowd.
In hindsight, the #1 reason why I've never smoked or drank alcohol is because I've never cared about fitting in. Peer pressure didn't work with me because I was always fine with being myself and couldn't care less if others thought I was "lame" or "boring".
Show me a person who doesn't smoke and drink and ill show you a person with a mind of their own.
I like people who march to the beat of their own drum.