The reason is Chinese people do not care for Koreans. With the Japanese, the Chinese hate with passion because of the war. Before there was any sino-Japan war, Japan was also unknown to most Chinese. Suppose Korea bomb a Chinese fishing ship, I assure you that Chinese people will be screaming to massacre Koreans as well. In any case, the great threat to China, and Chinese people is white people. Koreans are a pawn for the white race to counter a rising China.