How racist/denigrating/offensive is that riff anyway? Should it be avoided in mainstream pop culture?
... I have a feeling that there might be some kind of connection between the development of a need for a distinct, somewhat comical, caricaturic musical way of signalling Asia, and the apparent desire for material that ridiculed Asians or "put them into place." (Although it is true that more or less ridiculous musical clichés have developed for pretty much everything during the 20th century, in connection with the rise of cinema and television and their usage of background music.)(Via Metafilter.)
But I am no musical sociologist or such and don't really feel capable to connect the threads and interpret what the bigger story is which the rise of this cliché-phenomenon tells. And this project is still in the stage of gathering the evidence.