... Because Simon Cowell told him to. It's the only reason.
Cowell/Puppetmaster at large knows everyone loves a "celebrity spat" and someone he can usually rely on for that is Piers Morgan. TV presenter Steve Jones was appearing on his US chat show to promote - you'll never guess what - The X Factor, because he's not exactly wowing the American audience with his handshaking technique. Anyway, apparently Jones "stormed off set" when Morgan's questions "got too much." He proabably had the nerve to ask Steve what glamour sort he was currently doing (Keeley Hazell)
After the show the 34-year-old took to Twitter to write: "For the record I'm not ashamed to admit I stormed off @piersmorgan tonight. His line of questing was highly offensive. You judge #thisfriday." Piers, 46, replied to one fan asking who Steve Jones was (HAH!) saying: "No idea. Had him thrown off my set yesterday for lewd conduct."
Anyone who believes that this story is in anyway based in reality also doesn't question the existence of the Tooth Fairy and believes the X Factor isn't fixed.