I honestly think its difficult to separate alcohol & pot. Alcohol is legal but has greater and more frequent negative consequences. And pot is illegal!
I have no issues with people's occasional use of pot but do have an issue with daily use and see that as an unhealthy addiction (same views for alcohol).
I have tried it (don't like it) but I've tried almost everything and had some great times & don't regret it for a second! Thankfully though, I had enough sense to understand the dangers, knew where to draw the line and did not buckle to peer pressure. This is the most important thing as a parent as far as I'm concerned - ensuring children understand the dangers and are confident to say no. But some personalities are more susceptible to risk taking than others so don't quite know what the right approach would be.