Would you rather them being drunk, sleeping at the wheel, or talking on the cell phone, messing with the kids in the back, etc? Want them banned to?
I find it funny that alcohol is legal even though it is more addictive, kills more people (themselves and others) than marijuana, yet marijuana is illegal. No one has ever died by overdosing on pot, it is medically impossible.
Pot is far more dangerous than alcohol:
http://www.usdoj.gov/dea/ongoing/marijuana.html