These are mostly stupid teenagers well in their "this one thing about me is my defining feature phase" so you get the second or third generation teens who cling to this "ethnic" identity then get fucking pissed when some white person knows what bulgogi is because it throws off their groove.

Normal people, including those running the restaurants don't give a fuck because if you open an ethic restaurant in white suburbia and refuse to serve white people you'll go out of business faster than I can say "retarded".

Years back there was the great Kimono fiasco where a bunch of 2nd and 3rd or beyond Filipino/Chinese/Generic Asian ancestry kids decided to get all offended on behalf of the Japanese because some white people decided to adopt the Kimono as part of some fashion exhibit, when it got round to the Japanese media the general reaction was "the westerners like our culture? Great! Let's sell them more shit!" And they encouraged the fuck out of it, much to the annoyance of the race baiters.