Every success DOES need a guy like Greg. But I really worry about the part where Greg was working on the effort full-time, doing it all while the other guys still worked. When it ends in success, it is a great story. When it ends without success, Greg is the guy who put all his time into it, then ends up with nothing. Greg becomes the warning story. Greg is the guy you need. Not necessarily the guy you want to be.
There is a very, very fine line dividing "chief optimist" from "sucker."
Specifically for this context, if Musk and Altman conspired to do wrong by someone, it would be much easier to 'quietly beat them with a $5 wrench' than to engineer and construct OpenAI to publicly serve some cold dish. That's not to say it's all warm and fuzzy, but businesses that can succeed on aligned interests are better than those that seek cut throat markets.