I think while productivity shouldn't be the exclusive way we measure someone's life (and its implicit frame that someone's worth is measured by that person's material contribution to society), those dialogues hide a more interesting question -- how purposeful someone's life is, and whether regular, recreational use of marijuana supports or discourages living purposefully and meaningfully.

My experiences of marijuna is that it can loosen the societal conditioning on "productivity", and reveal the lack of purpose and meaning in one's life. It's liberating to realize the a lot of the conditioning don't matter as much as it seems.

It's at this point, that it's tempting to continue and just have fun. Here though, is the space in which one can discover one's purpose from within, with societal and external expectations muted. It's paradoxically that here, connecting with that purpose, brings life and joy outside of the mental states that marijuana can bring. When one makes conscious contact with that inner, unconditioned purpose, marijuna is something that is fun that one can occasionally enjoy, but not as a substitute for purposefully living.