Because dumbasses would abuse the right to have it
Carcinogen's:
Carcinogen's in marijuana - 50
Carcinogen's in cigarettes - 50
Weed - 0 : Cigarettes - 0
Addictiveness:
Marijuana:
less then coffee.Cigarettes: 90% addiction rate.
Weed - 1 : Cigarettes - 0
Death rates:
Weed: 0. Nothing. Null. Non-existant.
Cigarettes: ~500,000 per year. (according to google :s)
Weed - 2 : Cigarettes - 0
The list can go on. For a loooong time. You get sick if you smoke too much cigarettes, with pure weed, you don't even feel it.