It hasn't helped society, it has eroded our rights, and the drug usage hasn't been decreased much less stopped. Anyone who wants illegal drugs can get them anytime they want. And they do.
We are working on the wrong side of the equation. If you want to decrease usage you need to decrease demand. Supply will always exist to satisfy demand.
That is such a doped out lie. Let's say I want to buy some heroin to shoot up tonight. I don't have a clue where I could buy heroin and a hypodermic needle without any police hassles. In Florida they'll seize your car if you're found cruising for drugs.
If drugs were legalized I would know right where to go tonight. There would probably be 10 places in a 2 mile radius. Ergo you legalize drugs they will be cheaper and more available. Use will greatly increase since Americans lack discipline. But what to you care since you have the selfish, demented philosophy of libertarianism to justify stupid ideas such as open borders, gay marriage and drug legalization.