Don Rickles, the acidic stand-up comic who became world-famous not by telling jokes but by insulting his audience, died on Thursday at his home in Los Angeles. He was 90. The cause was kidney failure, said a spokesman, Paul Shefrin. For more than half a century, on nightclub stages, in concert halls and on television, Mr. Rickles made outrageously derisive comments about people’s looks, their ethnicity, their spouses, their sexual orientation, their jobs or anything else he could think of. He didn’t discriminate: His incendiary unpleasantries were aimed at the biggest stars in show business (Frank Sinatra was a favorite...