Kamiya calling people who are completely ignorant about Japanese culture "stupid foreigners" is pretty accurate. And btw, Americans do very, very often act in different cultures like "stupid foreigners". Comes with the empire, I guess. Stating this is not "racist" but "xenophobic", and considering the history of relationships between civilisations, xenophoby is completely rational and, at least for Japan, it worked. If they weren't as "xenophobic" as they were against the "Western barbarians", they'd be just another exploited, poor-ass ex-colony.
Anyone thinking that somehow xenophoby towards Western civilisation is not justified has to be completely ignorant about its history.