And if one doesn't understand the enormous difference between a pot smoker who takes LSD a few times year, and a heroin fiend, a crackhead, or an alcoholic, and cannot see that these things are not even on the same continuum, well then that person, well meaning or not, is talking out their arse.
I've seen and known people who have started with pot and marijuana who have continued with heavier stuff and died. Besides that, pot and marijuana aren't particularily friendly to the brain and body either.
As for LSD, it damaged the brains of talented people like Syd Barrett, Peter Green and Danny Kirwan among others.
I'm all for denouncing the heavier stuff. We've lost too many to that. Garcia, it was heroin. Janis Joplin as well. Morrison, alcohol + others.
No one's ever died of a marijuana overdose, unless they were diabetic and ate a pint of ice cream.
LSD - originally used for psychotherapy with great result and the potential to cure schizophrenia. Powerful stuff. Not to be handed out as candy, and with someone like Syd Barret, already mentally ill, there is real danger there.
No, I'm not pro-drug. But demonizing cannabis makes no sense, and only creates disillusionment in young people when they find they've been lied to. It also creates the allure of the forbidden. I'm for being real about this stuff, real about alcohol, tobacco, cannabis, and so on.
I think it's likely that people who go to heroin from marijuana are on that path whether they smoke MJ or not. The 'gateway' theory just doesn't hold up in the vast majority. I know dozens of pot-smoking people who keep decent jobs and don't become junkies. It's a difficult problem when someone goes down that road, but as Hank Hill says, "don't blame the beer."
Now, on to TOS:
Kirk: obviously Herbert. But as such, probably a hypocrite.
Spock: vaporizes before chess or vulcan harp playing. He reaches.
McCoy: doesn't strike me as one who would imbibe cannabis unless on rare occasions. Though if he did, he'd probably find Spock hilarious.
Scott: half a gallon of Scotch, please. Aligning the warp core drunk is one thing, but he'll be damned if any of his engineering staff be stoned!
Uhura: she's too professional. maybe off-duty but she would keep it under wraps.
Chekov and Sulu: used to share a joint before bridge duty, until that time Sulu tried making out with him. After that, not so much.