That is an incredibly ignorant which racist statement which I do not feel belongs on Hacker News.
It explicitly states that everyone "over the border" (in Mainland China) are the polar opposite of "genuinely lovely people" which would be to say that every single person living in/from Mainland China is a horrible/nasty person.
This is quite clearly both ignorant and racist - also, provably false.
Depends on who you ask. Race is a purely human construct (and a very nebulous one). The classification of 'human race' is entirely made up and has no biological science to it.
Ethnolinguistically Cantonese is very different from Mandrain. And culturally (in terms of diet, customs) Cantonese is also quite distinct from say Wu (Shanghai), etc.