You left out one other major thing, a ton of ethnic women follow what white women do (case in point: Asian American women). If an ethnic girl was born and brought up here in the US, she is going to have similar tastes and approach to life as your typical white girl. Often times these women will go for the same kind of men and have similar approaches to dating as your typical girl next door type of white girl. These girls will follow whatever white women are doing so it is stupid for any kind of ethnic guy in the US to ignore white women and disregard them since ethnic women themselves are the same way.In the U.S. and Europe, white woman are the majority. You are more likely to meet an attractive white woman than an attractive woman of another race. So due to sheer numbers, a lot of guys prefer white women. I would also say white woman are the most willing to date interracial. While Asian women are open to it too.. they usually stick to White guys like Nazi's and refuse to date anyone else.
So in summary, white women have the greatest numbers, the highest social value (due to racism) and are the most willing to date outside their race. Do the math.
Only exception is if you want to bang FOBs but limiting yourself a lot there.