Successful startups inevitably produce billionaires

Inevitably? What a dishonest stance to take. I sure do think that is a policy question as well as a who gets paid what question when it comes to achieving billionaire status, even for startups.

Could just be another way of saying that if you can't maintain enough growth momentum to make somebody a billionaire, then you wouldn't be considered successful.

At today's rates, I'm not surprised, isn't the dollar at an all-time low about now?

Certainly if success is judged by accumulating as much money as possible to flow in one direction, more so than all other worthwhile endeavors, then you should have lofty goals and it's pretty straightforward if the goals are purely financial.