While Marijuana may have uses for medicine. As a recreational drug, I think the in ability to easily check when you consumed it, or to have a high as a result of just burning off fat. (it is fat soluble, and you can end up high even years later if you burn enough calories) Makes it harder to enforce responsible use than say alcohol.

I don't think we want pilots, surgeons, or police doing their jobs while high, and since the buzz could come quite a long time after consumption that would always be a risk.

Hemp is often promised to be this miracle product that will solve all of our problems, but visiting places where hemp is legal we don't see massive quantities of it.

We import cotton, and bamboo, but you don't see many hemp t-shirts.

We even import paper, which is one of the things Hemp is pretty decent at. But we don't see much Hemp paper. Turns out ink doesn't stick to it as well as it does to Wood pulp and cotton blends.

The real reason Pot is still illegal is that it is dangerous to those who aren't consuming it. A stoned Doctor might not smell of it, might not have any real outwards signs, and then could get the giggles when he nicked an artery.

Edit: Years may have been a stretch. Looks like 7 days has been shown in a lab, and the CDC thinks weeks. http://healthland.time.com/2013/09/17/one-toke-many-hits-exe.... http://www.cdc.gov/mmwr/preview/mmwrhtml/00001143.htm