Well, just to play devil's advocate. If we keep pot illegal because it's got stuff in it that's bad for you, then why don't we also outlaw BHA, BHT, nitrates, nitrites, pesticides, petrochemical fertilizers, chlorine based products, all chemicals known or suspected to cause cancer, neurological damage, birth defects or other health problems, bacon, artificial sweeteners. Lots of art supplies too - oil paints, polymer clay (Fimo). Fiberglass insulation. Treated wood products. Formaldehyde. VOCs. Alcohol, psychoactive pharmaceuticals. Polyester, vinyl, petrochemical plastics, Teflon for heaven's sakes, and aluminum cookware as well as aluminum foil. Motorcycles. Diving boards and swimming pools, skateboards, snowboards, skis, .....
I could go on, but gee whiz, all kinds of things and activities have various benefits and risks that depend on chance as well as frequency and care with which they are used and undertaken. And medical bills to handle the bad results when things are misused, or accidents happen, can be high whether the causative factor was legal or illegal.
Our medical care delivery system is in worse shape than NOLA's levees pre Katrina, but I don't think keeping pot illegal is gonna work as a finger in the dike. Why not legalize it and tax it like tobacco and alcohol? The revenues could go into the health care fund for pot smokers, so they become self insured. Think of all the law enforcement funds that would be freed up, the reduction in prison overcrowding, the legal commerce etc.
Anybody read Michael Pollan's The Botany of Desire? Four sections, one on marijuana. Very interesting insight into how a generation or two of horticultural expertise has gone underground in cultivation of pot. What if all that suddenly was allowed to be legal in the light of day -- what benefits might be made available to the wider world around intensive agriculture?
There's an Amen in order from me to what you've said in the last paragraph.

