True dat. I completely agree with you. Life choices have absolutely nothing to do with laws - for some people. I would think that some people who have jobs dependent on drug testing would hesitate about partaking.
But that has nothing to do with the law. I knew a guy who worked for a truck company which wouldn't employ anyone who drank alcohol. Ya don't need laws for that.
Also, it depends on the person. You'd be surprised how many people fail piss tests on probation because they chose not to stop smoking pot (a non-addictive drug!) Dumbasses will always dumbass.