William Earl Robert De Niro worked the crowd at the Beacon Theater during the Tribeca Festival closing gala on Saturday evening, which served as a 30th anniversary celebration of his directorial debut, “A Bronx Tale.” When asked about the film’s mild box office — earning about $17 million on a $21 million production budget — the director said, “How could you not be disappointed? You do all this work for it. At the same time, I was lucky to be able to make the movie I made.” De Niro also admitted that “I never got asked to do movies after that,” and it was an effort to get his next directorial effort, 2006’s “The Good Shepherd,” made.