Certainly I agree that someone who works twice as hard as another should be allowed to take home twice as much money.
Likewise, someone who works twice as smart or twice as long should also take home twice as much.
And someone who works twice as long AND twice as smart AND twice as hard should take home eight times as much.
But how does that explain billionaires?
It doesn't.
People become billionaires not because they work any combination of that much smarter or longer or harder.
They become billionaires because they accumulated enough wealth and power to place themselves in a world governed by economic laws different from the majority of people--economic laws that reward the rich with more riches--not in proportion to how hard they work, but in proportion to how much money and power and influence they have.
Next, why should risk-taking be rewarded?
The bigger the risk, the bigger the fool is the person who takes it (unless it only seems a risk to the outsider).
And since such adventures are risky, the majority of people foolish enough to take such a risk will be hurt or destroyed for it; how is it good for a society to urge people to destroy themselves?
And how does rewarding foolishness fit in with rewarding merit? It doesn't.
Further, what's so great about being rich?
Do not most people dream of being rich so that they can live like leeches, without working hard?
I repeat: I've nothing against making more money than the next guy when such competition is in a level playing field.