My honest opinion - people who complain about others ethnic/racial preferences are insecure. they feel left out since somebody wouldn't consider dating them. It's also a symptom of PC society, since not finding x group attractive does not denote racism (which is defined generally as hatred or feelings of superiority over another race). Whilst the OP posted this nearly 7 years ago, I get the feeling his piece stems from insecurity (in somebody not digging him, and making a rationalisation to support his own biases).
I will admit I don't find some races/ethnicities attractive, but I don't at all and never have hated members of a race. IMO, it's no different from not liking blondes or brunettes. As everybody knows, anybody can have any dating preferences they want.