Why is Zhang Yimou called the Master of the Nation?

The reason why Zhang Yimou is called the master of the nation is because he had directed the opening ceremony of the 2008 Olympic Games, and the stunning opening ceremony at that time made friends from all over the world, guests from all over the world from which they realized the unique beauty of China and the image of a great country. Zhang Yimou also gained more favor and praise from the people of China. So since then this large-scale national event is generally by the master of the state to plan to host, so many people called Zhang Yimou master of the state.