Re: first things first...
>>turns out, banksters and CEOs are the LEAST useful people on the planet, BUT the highest paid; hospital janitors are the MOST useful people on the planet, but paid the least...
Pay is determined by supply and demand. Hospital Janitors are easily obtainable. Good CEOs, you might be surprised to learn, are not. It's often thought that CEOs are not worth the millions in salary or bonus because "they don't do any work", also.
Consider this basic thought experiment. You are the board of a company with a billion dollars a year turn over. There are quite a lot of such companies, as it happens. Suppose you have two candidates and the difference in outcome is a mere 2% to your yearly revenues. That is one will be this tiny little bit better than the other. That 2% equates to $10,000,000 difference in revenues. Ergo it is well worth paying a few million for the one that is better.
Furthermore, let us examine the related scenario where the difference in outcome of a CEO busting their arse all year and cruising along working 9 to 5 is, again, 2% difference to yearly outcome. Suddenly it becomes well worth it to the company to offer that million dollar bonus for doing well.
Now of course, 2% is just a figure I picked to illustrate. But having seen first hand at companies I've worked at the decisions of the CEO having a much greater effect than that, I think it's pretty reasonable as a way to illustrate their market value.
Janitors meanwhile, might as a whole be vitale to society, any given one of them however has low market value (no offense to any janitors reading this but I'm pretty sure they're aware they don't get paid much).
Your logic is honestly pretty bad. You sound like you've been reading that execrable pretence of statistics, Freakonomics by Steven Levitt.