I know you're being facetious, but it's much more difficult to evaluate risk/rewards ratio for drug use, and the motivation for engaging in it is less linked to this ratio than for other crimes.

Though I say that, and think back to Prohibition... which didn't involve the same addictive properties to which I'd attribute these properties of the War on Drugs, so I doubt myself.

I don't have answers either. You need punishment to prevent some crimes I think. But at some point it stops helping and it just hurts. Or perhaps we need another way to influence behavior. State mandated morality? Meh