Henry Ford revolutionized the business model by paying his workers enough to afford the automobiles they helped assemble.Ah, the demand curve is upward sloping! Of course, the truth is Henry Ford found a way to make his workers much more productive. He had to hire workers in a competitive market, so wages inevitably rose. The myth itself is self-defeating, how could Ford know how his employees would buy Model T's? Why not just give them a Model T's rather than income at retail value of the Model T?
Addendum: Within 1 minute of posting this, I Googled the myth and came across this article from the Mises Institute.