I don't think that's true. At least at the beginning, a "Greg" will be the person who has all the direct contact with mentors, investors, team, suppliers, and customers. A "Greg" will be the "business face" of things (not necessarily who the public see, but who everyone else sees). That's a very good position to be in when things fail or when the company exits.
CEOs go on to start something new. CTOs start interviewing for a new role. People who are a "Greg" find offers coming to them.