Unfortunately, a lot of people oppose legalization of drugs. Even marijuana - a drug with zero addictive potential and being massively recreationally used for generations, including by prominent public figures, without any serious ill effects - only slowly gains ground to be allowed to be used medically (that's while much more dangerous substances are actively used medically and nobody has a problem with that). 36 states allow medical use of marijuana, and only 17 states decriminalize it completely. And the federal ban remains, with laughably false classification of marijuana as a substance with "high potential for abuse and no accepted medical use". What to say about other drugs, with less established patterns of safe use?

I don't think it's "corporate stooges or obstructionist trolls" - people are just profoundly ignorant in the matter and are unwilling to change their minds about it, however large tall the most idiotic war of all wars takes. It'd be easy if it were just a bunch of corporate lobbyist trolls. Widespread ignorance is much harder to overcome.