He was called rude, annoying, vain, smug and mean. But Simon Cowell, the music mogul behind 30 hit singles and one of the creators and co-hosts of the insanely successful talent show “American Idol” (Fox, 2002- ), asserted that he was never nasty for sadistic reasons; he truly believed he was helping aspiring singers understand when they had no talent. “All we [were] doing [was] telling people who don’t have a chance in hell that they don’t have a chance in hell....