Eh, this seems like a blow below the belt to me. In a free society, American or Japanese, dumbasses have the right to speak their minds. (including NYT reporters)
Saying that racist manga reflects poorly on all Japanese is like saying Stormfront.org reflects poorly on all Americans. When a country has a population in the hundreds of millions, you can find several thousand who believe in anything.
DOes Storm front sells 300,000 copies of its book? That's fairly significant.