Let's not let this get nasty.
Way I see it, we may as well legalize it. Enough people like to partake in it that keeping it illegal just makes a farce out of the justice system. I don't think marijuana can be shown to be a direct cause in being a social reject - I know of writers (Pierre Burton - admitted "pothead"), CEOs, and <gasp> a President of the United States (who happened to be a Rhodes Scholar) who all smoked it. Don't see a direct link between pot and loser there (although I still feel Clinton was a putz).
Of course, you also have the losers who smoke pot, steal, get into heavier drugs and are generally a burden to society - but is this necessarily because they smoke pot? Perhaps they're losers because, like drunks, they don't really do anything productive with their time (preferring to feed their dependencies instead). Legal or not, it probably doesn't make a difference to these folks.
Screw it, if a guy wants to sit in his basement a smoke a joint to enjoy his evening, that's his prerogative not mine. Like our approach to alcohol, he shouldn't be able to do it in public (except in a specific location catering to it), he shouldn't be able to operate a MV or use a firearm etc etc, and it should be regulated in a manner which tries to cut organized crime out of it as much as possible (you don't see rumrunners and bootleggers hogging the Organized Crime headlines anymore, do you?). If the guy is an all-around douche-bag, then it probably isn't the joint he's carrying that we are going to be concerned about.
As well, this has nothing to do with the CF Zero Tolerance Policy, so don't throw it in as a red herring in an attempt to undermine credibility. As far as I see it, the argument concerns decrim/legalization within a broader social context. If you want to discuss the CF Policy (which, to me, seems straightforward), start a new thread.
