Critics have been clucking about celebrity casting. But so what? “If it takes a boldface name to bring out the crowds, so be it. Theatergoers aren’t chumps. They know Denzel Washington, who played Brutus last spring in the Broadway revival of “Julius Caesar,” is one of the best actors around, while Julia Roberts, who made her Broadway debut in Richard Greenberg’s “Three Days of Rain” this season, is a bona fide icon who has more depth than her film roles have typically shown. The Tony nominating committee may have snubbed them both, but these stars’ legions of fans couldn’t care less about such geeky honors.”