Well, the differences between western cultures are less pronounced, but I do think that knowing, say, Chinese etiquette when meeting mainland Chinese people is essential to not come across accidentally as rude. There are significant differences there, and natural body language does differ with culture.
Nonetheless, I agree with your general point/sentiment.
"Chinese etiquette when meeting mainland Chinese people is essential to not come across accidentally as rude"
For sure. And I read up about any culture I visit the first time. But chinese are quite different from mongolians and thais for example. So my issue was especially with "asian". This term is allmost meaningless to me, as it puts billions of different people in one basket.
Nonetheless, I agree with your general point/sentiment.