He co-founded and sold Segment. You think he was just at OpenAI to collect a check? He lays out exactly why he joined OpenAI and why he's leaving. If you think everyone does things only for cynical reasons, it might be a reflection more of your personal impulses than others.
Just because someone claims they are speaking in good faith doesn’t mean we have to take their word for it. Most people in tech dealing with big money are doing it for cynical reasons. The talk of changing the world or “doing something hard” is just marketing typically.