Coaches know that refs pay attention to the media, so it's part of a coach's job.
During a game, though, that kind of complaining can be a distraction to the team. And if it gets repetitious, it can really cause trouble. The bottom line is, Dunleavy just wants to make the officials aware of Shaq's swinging elbows, and Nelson wants them to see the Jazz flopping. But, usually, the officials disregard all of it. But in the postseason, the good teams have so much time to prepare, especially in the first round, that a singular offensive focus becomes a huge disadvantage.