My thoughts on the subject are mixed. I know many people who are pro-cannibis are going to disagree with me whatever I think, but I figured I'd express my opinion despite the way the poll turned out.
While the mighty ganja might not be worse than alcohol, I pretty much feel that the more intoxicating substances that we can limit, the better things are. Whatever stats might be quoted, the bottom line is that putting pot out there is going to create more intoxication and accidents. Not just motor vehicle related, but in general.
Pretty much all the reasons why people want to get stoned, and all the crazy stuff they do under the influance are good reasons why it shouldn't be allowed. We're not talking about violence, so much as general idiocy. Generally speaking pro-pot proponents will be very quick to point out how harmless weed is when making a case, but at the same token when you look at the stoner sub-culture they themselves present it as being anything but. If you look at things like old "Cheech and Chong" movies, they are quite funny, but the problem is that in real life a lot of the stuff in that movie would get people killed. The idea of the two of them driving a car while so stoned that they crash, and don't even realize they're not driving anymore for hours... well that's not quite so amusing when things like that happen for real (and they CAN happen, which is why it's funny). Pretty much all the "this one time when I was stoned out of my mind..." stories pretty much form a solid counterpoint to most claims of the drug being harmless.
On top of this, while not quite on the level of a movie, weed can get people intoxicated through secondhand smoke, especially if a lot of it is being consumed in one area. What's more it's also very fragrant and sticks to clothes, being far worse in this respect than cigarettes. It infringes on the rights of people who just happen to be present when someone else happens to be enjoying a fatty.
Simply put I feel the cons greatly outweigh the pros, and it's also one of those things that can heavily infringe on others. You aren't going to get drunk by simply being around a lot of people drinking, nor is some dude downing a bottle of rum going to make your clothes stink. Although arguably the behavioral aspects are just as bad.
Consider also though that I am also a supporter of "The War On Drugs", and I also think that the probition was not a bad idea. I also think that one of the big problems with the alcohol ban was that we didn't stick with it. You aren't going to see results even in a few decades, for something like that to really work you need a few generations to pass in illegality. The generation that was a problem to begin with is not going to ever be entirely clean due to the cravings and such no matter what laws you happen to pass. This means that before anyone can weigh results, you need to wait over 200 years given the fact that people today can easily live to 80 or more, and when dealing with social engineering you need to look at the results on people that had no real contact with the generation where the problem existed. This is in part why I also feel that people who complain about the "failure" of the war on drugs in general are wrong, because I don't consider it to have started in earnest until Reagan was in power in the 1980s. Around 2180 we can start looking at results, assuming of course we get serious about it, which has always been a big part of the problem. Domestic policing is fine, but the issue is international cartels, which need to be targeted more directly irregardless of national sovreignty I feel. I'm one of those guys who basically feels that if the police in another country aren't meeting results due to widescale corruption, and groups like the CIA and intelligences services with satellites can see some of these operations making the junk, which gets packed up and sent to the US... well that's the time you fly in a bunch of jets and just bomb the living bejeebus out of them. If Civilians die, well... that's war, it's no worse than when we bombed civilians, and even our own people (forced to work as PoWs) during World War II to destroy Germany's infrastructure... and not all of those factories were building weapons and bombs. Some feel I'm crazy, others not so much, it largely comes down to your take on morality, and whether you support the issue or not. I see it mostly as declaring war against international drug cartels, as opposed to on a nation. I do not believe (personally) that nations are the only viable grouping of people to declare war on.
At any rate, apologies about the rambling, I'm pretty tired but can't sleep. The bottom line is that I'm very much against "drugs", even alcohol for that matter. Truthfully I'm a bit more sympathetic towards things like Heroin (coming from poppies) because at least that has some legitimate uses as a painkiller, even though there are nowadays better ways of acheiving the same result. I don't approve of it for recreational use, but I can see why it might be manufactured in places as outdated as it might be. All studies aside, I am not sold on any practical use for smoking weed other than it's fun, and feels good. What's more even with studies claiming medical benefits, I feel there are usually other ways of acheiving the same, or similar effects. Much like how there are alternatives to Heroin, which I also agree with being illegal (my sympathy only being because of it's backround and uses, it probably helped save a lot of lives through the years).