The humor is annoying, degrading but sometimes entertaining. As an Asian, I can relate to a number of cultural and racial reference and nuances, thus my amusement. I'm aghast though that the characters do not speak nor behave like Koreans at all (I've watched too much K-drama to know this).
I'm surprised why Koreans have not cried foul over this for it to continue running for 5 seasons. Probably like mehl, those who are appalled shouldn't take this series seriously.