Why do Americans think just because the Coronavirus originated in China, it's an excuse to be racist to Asians?

I think the black plague (which came from central Asia) and the mongol invasions of Europe are good enough reasons for white people to be "racist" against Asians.

Chinese people aren't the only Asians. I don't think other Asians should be bullied just because of Chinese people. Besides whatever I said, Chinese people are barbarians uncivilized people who eat anything they find in their way. Ewww!! They eat dog meat, bat soup, raw frog, cats and fertilized eggs. Fvcking sh!t.... 

I will never go to China and eat Chinese food. Stupid dumb retards are they. China needs to be bombed with nuclear bombs.

China is just one of the forty eight countries in Asia. Many Americans think that "Asian" refers only to China, South Korea and Japan when it has a far broader meaning than that