Who can build a yacht by themselves?

Right off the bat, I want to say that I am neither conservative nor liberal, neither socialist nor laissez-faire capitalist. I just think that everybody should be given a chance to make their own way in life and have to work to get there, neither being abused and manipulated by higher powers nor taking extreme advantage of those in lesser circumstances. To what degree social programs exist to help the poor and equalize the playing field is a topic for another day, what I want to talk about now is the super rich and just how much work they have put into getting that way.

How much of what the super rich have did they earn and how much fell into their lap by way of birth, luck or taking advantage of lower classes and how much came through their hard work and ingenuity? I would guess that no matter how hard someone works and no matter how smart they are, hardly anyone on earth is more than 5 times as productive as the average person. Maybe if you have insomnia, aspergers and an OCD induced obsession with your work you could be 10 times as productive as the average person but that would be very rare. If virtually nobody is more than 5 times as productive than the average, how can it be ethical for them to get more than 5 times the pay?

What does a yacht cost? maybe $10 million? Some people can afford one, but could any single person build one? I don't care how smart, talented, resourceful, educated, hard-working, or gifted you are, no single person could build one in their lifetime. So how could anyone ethically earn enough money to buy one? If you have enough money to buy a yacht, you obviously got a good chunk of that money off the backs of other people. You could NOT have earned it all yourself. Even if it was legal, that doesn't make it moral or ethical. Plenty of things are legal but immoral just as there are many things that are illegal yet still ethical.

So what's the ethical thing to do? Impose salary caps. Nobody in a corporation should be allowed to make more than 5 times what the average employee of the corporation makes. The money above 5 times the average should then be distributed evenly among the rest of the personnel. This would achieve two big things, Although it is impossible to truly put a price tag on an individual's worth to a company, there would at least be an ethically reasonable ceiling. Second, There would be much more incentive for underlings in the company to work hard since corporate profits would return directly to the people doing most of the work. As it is now, few employees see a monetary benefit to working harder than the minimum expectations. If they knew that their hard work would come back to themselves and coworkers in bonuses, people would feel much more invested in their work.

This plan would not affect the corporation's ability to reinvest profits either, as it would only affect salaries. It would be socially responsible yet still capitalist.

I would be interested in the opinions of economists and businesspeople on this post