While you might argue which drug is dangerous and which isn't, ban on drugs is not arbitrary decision. You can't do whatever you want with your body, because you might loose control and hurt others. Drug abuse affects others as well (financially, mentally, physically...). I am victim of someone's drug abuse. I never took any drugs. So if you are looking for victims of drug abuse, here I am.
> You can't do whatever you want with your body, because you might loose control and hurt others.
Why is it legal to drive a car, then?
Some of the decisions were rather arbitrary at best, and racist at worst, though. The sentence disparities regarding, for example, cocaine depending on how you are using it was designed to punish black people more harshly. Opium bans had as much to do with anti-Chinese sentiment than anything.
I'm not arguing that drugs should be legal, but we do have to be clear that the reasons for banning them and the punishment are not necessarily rational.