Actually, the hero was Paul Proteus and I believe he was actually being promoted not fired. He questioned the system by stepping outside the box, so to speak, and evaluating how a man measures his own self worth. He is exposed to the elements of the base, lower class society and was left cold by it.
There was, however, a character in the novel that developed a machine that did his job better than he did and was laid off.
It's interesting to note that Vonnegut wrote this while they still used vacuum tubes in computers. The master supercomputer that he describes in the book takes up acres upon acres of space. Still, the irony of his prophetical message is not lost in nostalgia as we very nearly live in the world that Kurt Vonnegut, Jr. envisioned. A world run by machines.