its only natural for asians to like asian girls. attraction, and interpretation of beuty is kind of a genetic thing.
however, modern age teaches racism is bad

cos it is

they are a different breed of human, but are still humans.
basicly, its a question of, do you want to have pure-bred offsping and have several different breeds of human, or not, and have just 1 mixed crossbreed? AG being asian only likes asians, so i presume he's a fan of genetic purity, and not 1 of cross breeding

IE, he's listening to his genes.