The opening night of Washington National Opera’s final production of the fall, Giacomo Puccini’s Madama Butterfly, offers yet another opportunity to wonder why in the world this opera remains so popular with American audiences. Most opera fans, myself included, love this opera because the music, especially for the title character, is some of the most memorable that Puccini penned. However, the libretto by Giuseppe Giacosa and Luigi Illica tells a story that should inspire disgust….