Henry Ford did more than gain & spread wealth; he actually created wealth. With his ideas, business practices, and innovation, he revolutionized an entire spectrum of manufacturing around the world, and actually created value out of that which was less valuable. That's what happens when you build, you create, and innovate. You create something where nothing was before, and in doing so you provide paying work for those who did not have it, and jobs where there were none. It's the American dream.
Wealthy people gain, yes. Middle class people can gain as well, if they are hard-working, innovative, and thrifty. But, once they do that, they are not middle class for long. They become wealthy. It can go the other way as well; a member of the middle class who places more value on a plasma TV and a Cadillac than on savings & investment can become poor, if their only source of income suddenly dries up.
The upshot is; you can have anything, if you are willing to work & sacrifice for it, and don't do things that will handicap you in the future. (have kids too soon / out of wedlock, spend all your cash on partying & toys, etc.)
Work hard & smart, America... we can get through anything if we do.