This is like saying "If everyone stopped having sex, we could eliminate STDs, abortions, and unwanted pregnancies." True, but absurd — not even worthy of a science fiction short story.
Indeed, anyone who complains that everybody should just stop taking drugs is basically admitting that they have no remotely reasonable ideas for dealing with the problems that result from drug use. We, on the other hand, have lots of ideas about that. And unlike the ridiculous strategy of trying to end all drug use, our plan for ending the drug war instead seems to be looking more realistic every day.