Allow me to create an antithesis to this thread's original aim: I'll roughly dissect the generalized group of "psychoactive drugs" into a separated list, where I will place judgments on their moral values towards society and individual humans (historically and potentially).
Opiates - good when controlled for medicinal use, terrible in almost every other case otherwise.
Alcohol - good when in very moderate amounts, terrible when it's the only societally-endorsed recreational drug.
Marijuana - good in moderate amounts to spur creative and progressive thinking, slightly bad when users are oppressed.
Psychedelics - very good for personal growth and therapy, bad when used incorrectly
Amphetamines - good if you want your kids to become drones and your jet fighter pilots to be sharp, pretty terrible otherwise
Cocaine - same as opiates.
Dissociatives - great for anesthesia and a strange sense of psychedelia, but slightly addictive
Tobacco - not many positives
Medicinal herbs - very nice
Nootropics - great brain stimulants, especially if a plant extract
Overall most of the negatives from "drugs" come about due to a few overarching themes: addiction, societal oppression, and misuse. Personally, I believe that if society came to a point where it could embrace psychoactives for what they are and what they can provide, then the risks can be minimized in every respect. Controlling certain drugs, such as unnaturally refined opiates, amphetamines and cocaine, should be a concern, but also the allowance of psychoactive use recreationally and spiritually should certainly be allowed for the general population. I truly believe that the rampant chaos caused by alcohol is a result of oppressing many safe avenues of psychoactive drug use while allowing but one traditional, yet potentially deadly and chaotic form to be used.