Is the point you advocate ruining peoples lives on the off chance they might develop a condition they would develop anyway? If that's the case, let's outlaw coffee a drug you are likely addicted to and has more of a chance to adversely affect you, even kill you.
Heavy coffee consumption linked to higher death risk
The active ingredient in coffee, caffeine is a mind altering substance that if you take enough will kill you.
Documented Deaths By Caffeine
Now you show me a single study that shows a single person dying from an overdose of THC. I'll save you the time, there isn't one. So let's outlaw coffee, and start putting folks like you in jail to save you from yourselves. Do you think that is a good idea. Bet you don't...
Oh by the way, the only reason marijuana is illegal is because people some time ago thought it made black men chase after white women.
Marijuana Prohibition Was Racist From The Start. Not Much Has Changed. | The Huffington Post
And the reason it remains illegal is a combination of a for profit justice system, and drug industry that depends on it being illegal. Without weed being illegal we wouldn't have the highest rate of incarceration in the world. And the most expensive drugs in the world.
Prisons, Jails, and People Arrested for Drugs | Drug War Facts
New Study Has Big Pharma Terrified -- Pot Destroys their Profits
And not to mention law enforcement depends on weed being illegal to keep their hefty budgets.
http://www.prohibitioncosts.org/mironreport/
All that for something less harmful than the coffee you drink in the morning, how do you justify this disparity in freedoms as an American, American...