it's supply and demand. 1. the supply of thin women is low in murica so being thin already puts a woman above average in attractiveness (asian women are thinner on average)
2. the supply of attractive asian women is low in murica (when compared to asia) so dudes (of any race including asian) who are into asian women have to settle for the ones (far) below their level.
this is why an average or even below average (not fat) asian woman from asia moves to murica and instantly sees a massive increase in her value. the reverse is also true, murican men (including asian murican men) go to asia and see a massive increase in his value.
also face blindness : p