I agree -- on two conditions:
a) If the society consisted only of adults and,
b) if the adults took full responsibility for their actions and did not rely on the rest of us to care for them.
Since neither exists and will never exist, my answer is ... no.
Since neither exists and will never exist, my answer is ... no.
And your point corresponds with my own personal feelings on the subject. If you are rich, and you can afford to live without taking money out of someone else's pocket to pay for you food and shelter, and if you keep your drug usage to yourself and not try to spread it to anyone else, and if you have no dependents who must rely on you for their living, then I say go ahead and smoke, shoot-up, or pill pop your brains out.