Here's a possible alternative view of the thread thus far.
Hey man! Let's go smoke some, I've only been brainwashed by my peers that this is a great life without any down-sides, and that only boring people don't do drugs.
I'm ambivalent, but as long as the marijuana doesn't affect their life to the point it affects you negatively, I would be fine with it.
No, I prefer one vice rather than two in my life. I would rather drink instead.
No, I prefer not taking or needing any drugs to be happy with my life.
No, people who smoke (or any drug) continuously can have psychological and possible physiological dependency issues on it and I would prefer not having to deal with the complications of a relationship from that.