Atlas Shrugged...What is the meaning behind the passage?...?

Question

Francisco D’Anconia: “ … why is it that throughout man’s history the Nat Taggarts, who make the world, have always won—and always lost it to the men of the Board?"
Dagny Taggart: "I … don’t know."---Part 2, Chapter V

Answer 1

It was the last fictional book of Ayn Rand before she devoted her writing to philosophy, politics and cultural criticism.
She considered it her "magnum opus".
The theme of Atlas Shrugged is the role of the mind in man's existence and, consequently, presentation of the morality of rational self-interest.[1]

The main conflict of the book occurs as the "individuals of the mind" go on strike, refusing to contribute their inventions, art, business leadership, scientific research, or new ideas of any kind to the rest of the world. Society, they believe, hampers them by interfering with their work and underpays them by confiscating the profits and dignity they have rightfully earned. The peaceful cohesiveness of the world requires those individuals whose productive work comes from mental effort. But feeling they have no alternative, they eventually start disappearing from the communities of "looters" and "moochers" who bleed them dry. The strikers believe that they are crucial to a society that exploits them, and the near-total collapse of civilization triggered by their strike shows them to be correct.