Sidney Poitier, who was Hollywood’s first Black matinee idol and who helped open the door for Black actors in the film industry, died last week. He was 94. For Wesley Morris, a Times culture critic, it is Mr. Poitier — not John Wayne, Cary Grant or Marilyn Monroe — who is the greatest American movie star. “His legacy is so much wider and deeper than the art itself,” Wesley said. “This man has managed to affect what we see, how we relate to people, who we think we are, who we should aspire to be. And if that’s not a sign of greatness, I don’t know what is.”