Ancient China had tons of courtesy in social interactions, and used to consider other countries uncivilized. The lack of courtesy in Mainland China is due to the communist revolution, which promoted tough fighting mentality to break social hierarchy and order, and threw away traditional values. It's an aggressive way of promoting equality. The revolution is over since Chairman Mao left. Now that the Communist Party is the governing party, the emphasis is hierarchy and order, or in a better sounding word -- stability, so that they can stay in power forever. They try to bring back traditional values, but the revolutionary damages are hard to overcome.