I think the whole straight edge thing is an attitude more then anything else. From my expereince people who consider themselves straight edge look down their noses at people who do drink/smoke ect.

It seems to me it's not you're attitude (since you just said you don't think less of them) and more just your preferences. I have a friend that's like you in that respect.

It's like. . .you can't be an athiest without being passionate about it, then you're just agonostic (or antostic. . I get those two mixed up). To give an example.