I think it was a real mistake to create OpenAI as a public charity and I would be hesitant to step into that mess. Imagine the fun when it tips into a private foundation status.
Was it a mistake to create OpenAI as a public charity?
Or was it a mistake to operate OpenAI as if it were a startup?
The problem isn't really either one—it's the inherent conflict between the two. IMO, the only reason to see creating it as a 501(c)(3) being a mistake is if you think cutting-edge machine learning is inherently going to be targeted by people looking to make a quick buck off of it.
I mean that's certainly been my experience of it thus far, is companies rushing to market with half-baked products that (allegedly) incorporate AI to do some task or another.