Not so long ago, Simon Cowell was probably the most powerful man on American TV.

His cranky, caustic judging had helped make "American Idol" an invincible No. 1 hit. As a producer, he makes "America's Got Talent" and similar shows that have long been top sellers around the world. He ranked No. 17 on Forbes' 2013 Celebrity 100 list, with estimated annual pay of $95 million, and famously predicted that his own "The X Factor" on Fox would hammer "Idol," the singing contest he left in a storm of publicity in 2010.

And now? The hanging judge has fled the stage like a bad karaoke singer, leading many to wonder if the rapidly changing TV business has outrun even someone as savvy as Cowell.

Earlier this month Fox abruptly canceled "X Factor" after three troubled seasons and after a top executive at News Corp., which owns Fox, slapped the show for "disappointing" ratings. Likely to blunt the media impact, word of the show's fate came late on a Friday afternoon just as the American broadcast of the Winter Olympics was getting underway. Cowell — who suddenly has no on-camera platform on a U.S. TV series for the first time in well over a decade — was reduced to explaining the "X Factor" bomb to his 9.4 million Twitter followers.