Bud Simons is a longtime friend of game producer Warren Spector, who avid Wild Cards readers may recognize as having lent a name to Bud's most beloved character, James "Demise" Spector. When it came time for Warren to create a boss monster in his blockbuster game, Deus Ex, he decided to return the favor--and thus, the Walton "Do you have even a passing interest in doing your job?" Simons supervillain was born.
Since the game's debut, Walton Simons has become such a part of popular culture that he is listed on the Wikipedia entry for FEMA. That's the actual FEMA, not the Deus Ex FEMA! The character was named the fifth greatest villain in PC game history in the April 2006 issue of PC Gamer magazine.
Here's the Deus Ex character's "official" biography, taken from Wikipedia.