I was quite wrong about this, but I still don't think it's especially relevant that someone else built it. You would never call Zuckerberg an operator? Or when someone else built it does that not mean that you had no role in building it? That would be the exception, but it would be analogous to owner/operator in general business parlance.
Edit: here's a post with "Founder Operators". Which seems like maybe if you just heard "Operator" you would assume they're not a founder, but also that the term can be applied for those running businesses they founded: https://startupceo.com/2023/01/5-things-successful-founder-o...
I think now, having tried to fill in my missing knowledge, that it comes from the same root as DevOps, which I erroneously thought was related to SpecOps. DevOps comes from IT Operations which comes from Operations Management, which yes, is like a machine operator. https://en.wikipedia.org/wiki/IT_operations https://en.wikipedia.org/wiki/Operations_management
Edit: here's a post with "Founder Operators". Which seems like maybe if you just heard "Operator" you would assume they're not a founder, but also that the term can be applied for those running businesses they founded: https://startupceo.com/2023/01/5-things-successful-founder-o...