First of all, IF one were to 'do drugs' I think any discussion should only apply to persons of an adult age, when they are of sound mind to chose to do drugs. If you do drugs licit or illicit [legal or illeagal] before your brain has fully developed, then the chnaces are, you'll suffer some form of mental illness, especially after prolonged use.
All that being said, I am fine with cannabis [though I currently don't take any illicit drugs]. I also think in a controlled environment, Magic Mushrooms are good.
Their is a long list of 'drugs' that I think might be acceptable for occational use in a controlled environment. If their is a hint of dependancy, or abuse such as being under the influence in public, over use, mental illness etc, etc, then it's end-game.
Drugs like Cocain and Heroin are fine for medical use [actually, we need them], but for recreational use, they are evil killers.
I guess the hate of drugs is something that we've learned from other people. We don't actually know all that much to condemn or condone them, but we are getting there.