Can someone please explain why everyone seems to hate Koreans in this (￣∇￣") I’m s...

Its just Taehee. I dont think he's comfortable with Koreans (especially those who grew up in Korea) because even if he is Korean, he acts more western than asian.

And trust me, when the way you look doesnt match how you talk, act, or think... theres a sense of isolation within that ethnic group for not being Korean (or whatever race concerned) enough.