Since this is something I spend a lot of time noticing, and I find discussions circling ethnicity to be shallow and immature, I had to reply:

Men of the same ethnicity have better luck because of the pressures of culture put upon women to marry within that culture. The odds are in their favor, save except a large portion of the Caucasian population without social or religious ties. Men of a different culture pursue women of a particular culture based on the misconceptions or preconceptions they have of women of that culture. Such as “asian women are obedient” which was a prevailing thought until the 90s and probably still persists. Exemplified in the film Loverboy. What you should be asking is why do the majority of women now, who are the supply that’s in demand, refuse to take the reigns in the mating paradigm and shake things up? They’re content taking the easy way out.  Letting the inmates to run the asylum.