The productivity of the "rich" is more likely going to relate to their ability to do things for the corporation that the janitor and floor-worker just can't do. And they are paid in relation to that ability.
So, how much can an individual really EARN, in a year or a lifetime?
Certainly, delayed gratification is valid - Sacrifice early on and get paid more later on.
Just for round numbers, I propose that one can EARN an average of $1 million/year over a 50 year working lifetime. That is, $50 million for that working lifetime. Anything above that $50M is windfall profit.
And we have individuals getting paid $100,000,000+ a year. Is it possible to EARN such a thing? I say, NO WAY IN HELL! And to do such is an undesirable distortion of (ideal) capitalist theory.
Moose