I woke up this morning feeling guilty, ready to admit a journalistic lapse: I watched only about five minutes of last night's marathon season finale of "American Idol." That's partly because I've never liked the show, and partly because both the Red Sox and Celtics were playing on other channels. But I'd meant to tune in last night to watch Simon Cowell's swan song. Even though I'm no "Idol" fan, I've always thought Cowell's style, while over-the-top, is relevant for managers. Cowell rose to fame and fortune on the basis of his brutal honesty, ignoring conventions of politeness to give candid feedback. Yes, he's unnecessarily mean and nasty — hey, it's a TV show — but he's also one of the world's foremost practitioners of a word that pops up in HBR every so often: candor.