As a person who believes strongly in personal freedoms, thank you for saying this Paul.
If someone chooses to consume a drug of their choosing and still create in a way that fulfills them and their customers -- it is a grave injustice to shackle someone, wag a finger and tell them no. You inspire on many fronts.
I don't mean to sound glib, but I'd think you would -- less for the social stigma or potential for doing something idiotic while stoned, but if I were about to invest a significant amount of money in a company, I think I'd consider 'probability of a founder going to jail' as something that mattered.
The odds of going to jail in California just for possession of a small amount of marijuana are somewhat lower than the likelihood of going to jail for speeding. As long as the founder is not dealing, I don't see why you'd worry. Particularly since many Californians use it legally.
I suppose that matters if the team plans to move to / stay in or is already in California. I personally don't have any opposition to it, but outside of California, it's much less forgiven by the legal authorities.
It's pretty forgiven across the board these days. There are states / areas in states where it is absolutely not, but the majority of law enforcement members, in the majority of areas, don't give a shit about some kid cheefing away on a spliff while typing a lot, or playing music, or whatever it is they like to do.