Is it racist to want sushi chefs to be Japanese?

Recently a Seattle sushi restaurant, Mashiko, posted an open letter on its website saying that people who criticize the restaurant for having non-Japanese employees sushi are bigots. “Stop being an ignorant racist,” the letter said, after noting that the restaurant is Japanese-owned and there are Japanese as well as non-Japanese staff. The letter also defends one of the restaurant’s most popular chefs, a Caucasian woman, who’s worked there for 12 years and has a loyal and devoted following. “Should you refuse her fare based on her gender or race, you are an absolute fool,” the letter states. I feel for the staff and owners of Mashiko, and I’m surprised that diners in such a great foodie town as Seattle would be so unsophisticated that they’d make decisions on food quality just on a racial basis. Still, I think this is a much more complicated discussion than just bigotry (though that's part of it, for sure).