In Los Angeles there’s a pretty good chance someone who had something to do with making that movie is in the audience. Or there’s at least a relative or friends, who will relay the positive response. In certain other countries there’s probably some CGI person who appears in tiny print after the mid-credits teaser scene. They are more likely to get a kick from applause than the director, too, since they don’t parade around the talk-show circuit. I’m not saying it should be expected, but if people are really delighted, they should go ahead and express it. Joy harms no one.