I'm loathe to ban anything, but a healthy society wouldn't do drugs. If the sheep just knew better and did productive things with their lives instead of indulging in vice and shallowness, then banning it wouldn't be a discussion.
Society has largely moved on from cigarettes even though they are not banned. OK I know they've been taxed heavily and advertising is banned, but the point is the same - If people aren't interested or better yet, they know better than to take this stuff, there won't be a big market for it.
Drugs are in the same category as P**N, alcohol, and the new︀ kid on the block: Phone addiction.