I really don’t want to get bogged down in this argument but here are a few now known facts and observations on pot:
Marijuana smoked is at least, and potentially more hazardous to one’s health than tobacco is. It is a carcenogen and can cause most of the same problems tobacco can when smoked. Because it is unfiltered and usually smoked down closer to the end of the joint, blunt, whatever, it also gives the user a far larger dose of the bad stuff that is essentially the same as a cigarette.
Long term use causes a near 19% increase in the chances of developing a bi-polar disease. While it can alleviate some symptoms of schitzopherena it aggrevates conditions like manic depression severely.
Because THC can be retained in the body up to 30 days there is also going to be a major problem in its legalization over legal issues like effects on a user operating a vehicle, or machinery at a place of employment.How would a scenario with legal recreational marijuana be handled if say a commercial pilot or driver were in an accident? Since THC could be present up to 30 days after use even very occasional use could cause legal issues over liability.
With that said, I could see reducing the criminal penalities on it substancially while keeping serious civil penalities in place.
As for its comparison to alcohol this is just a post hoc promter hoc logical fallacy. The two are two seperate issues and trying to compare them is an irrelevancy. Yes, alcohol creates social and legal problems but those are seperate from the ones marijuana causes.