Ah right, I was referring to distinction between "problematic" and "non-problematic" use. People generally accept that you can have a "non-problematic" use of alcohol but not everyone accepts that for the other drugs. Although you'll still find newspaper editorials concerned about teenage drinking. And in the really regressive papers, concern about women drinking.
While cannabis simple possession is very rarely prosecuted the police are still going after grow houses. I think it would have to be legitimised (properly legal) to see a decline due to losing the "rebel" factor.
Well, maybe. I don't think smoking cannabis is really seen as rebellious these days, though.
I don't see any reason to believe that legalizing a drug will stop people using it, or cause them to use it more responsibly than they do currently. We have a case study in the form of prohibition in the US. There's certainly no evidence that alcohol use declined following the repeal of prohibition.
While cannabis simple possession is very rarely prosecuted the police are still going after grow houses. I think it would have to be legitimised (properly legal) to see a decline due to losing the "rebel" factor.