Mario Vazquez was on ‘The Late Show with David Letterman’ on Tuesday to give the ‘Top Ten Reasons I Left American Idol’… Well, not quite ten. Read the list at CBS.com and check out more on Vazquez’s interview with ‘Entertainment Tonight’ host Kevin Frazier, and a clip from his ‘Late Show’ appearance, on ‘The Early Show’ this morning via CBSNews.com below.