I don't think anyone's suggesting we legalize weed and give people immunity from prosecution for driving high.
Marijuana is safer than alcohol. Too much alcohol will cause death. You cannot OD on marijuana.
Marijuana is safer than Tylenol which a kid can buy over the counter in a store. Too much Tylenol will shut down your liver. You cannot OD on marijuana.
Repeatedly punching yourself in the face causes brain damage. It's a dangerous power every kid in the world has. But putting them in straight jackets is not a good solution.
Recreational use of Marijuana is bad. However I do not believe the answer is suppression and control.