Not fussed about it. I've seen someone I used to know get into a really bad way due to drugs (not just weed, but it was a big part) and now he has schizophrenia, so yeah not bothered about it. I know it may be an isolated case but it's enough to make me value my normality.
I don't enjoy the act of smoking cigarettes either so I guess that helps too. I don't object to it though. People are free make their choices. They just have to deal with any possible repurcussions.