Why did Saturday Night Live alum Chris Kattan get fired from Stephen Sondheim’s “The Frogs” on Broadway? “The departure of Kattan from ‘The Frogs’ could be turned into a sort of morality tale — or fraught disaster movie. After all, what could have been more promising and foolproof than to be summoned, as he was, from Hollywood to Broadway by some of its most dazzling citizenry — multi-Tony winners Stroman and Lane, not to mention Sondheim? They invited him to take his first role on the stage.”