Chinese are very Xenophobic and racist last time China brought a lot of Africans to study in their country the Chinese were killing them for fraternizing with the local girls.
China is a uni-culture and 90+% Han Chinese.
Everyone needs to remember, “multiculturalism,” “diversity,” racial-pandering, etc... are all American/Western concepts, and new ones at that.
That’s not to say Chinese hate others, and certainly this man is probably mentally ill - but like many peoples, they believe their race and culture is “the best.”