Pretty sure that if that was the only reason, and they had him cornered like this, he'd abandon PanoptiCoin. Nobody, not even he, thinks it is remotely close to the relevance level of OpenAI.
Yeah, I strongly suspect there’s some kind of self-dealing/conflict of interest going on here. It’s one of the few things that would explain an immediate, public ouster. Undisclosed contracts that violate some kind of board prohibition would also qualify (e.g. military, as some others have speculated).