Earlier quoted context omitted.
I can say "I don't find most Chinese women attractive". Or I can say "Chinese women are so ugly, I cannot understand how people manage to reproduce in China". Do you see the difference? One statement is not racist and the other is.
Actually both are not racist. Both are subjective statements. One needs not explicitly add "I, personally" to his personal correspondence. "Chinese women are so ugly, I cannot understand how people manage to reproduce in China" should be read as: "I find Chinese women so ugly, that I cannot understand how people manage to reproduce in China".
It's understood that in personal correspondence everything stated is the opinion of the author. Both my fictional examples were written from a personal point of view.
The actual difference was that one expressed a personal preference without being offensive; the other called a vast group of people "ugly", which is offensive, and expressed incredulity that they even managed to find each other sexually attractive enough to reproduce (which is naive as well as offensive).
Racism is primarily subjective, so that's no excuse either. Rational justifications for racism are more often than not a posteriori justifications.