On that front, how many western style fantasy settings mash all western cultures into one mishmash but supposedly homogenous and unified 'occidental' nation like you so often see with exotic far east 'oriental' settings? Do they have a pantheon of gods that include Odin, Zeus and Jesus Christ analogues next to lesser gods Santa Claus, the Easter Bunny and Krampus? Do they have wild west cowboys in the wide plains next to knights in manors next to French-style musketeers? There may indeed have been such a thing but I hope you do see how taking license with distinct cultures from a region dissimilar to your own can produce something way too silly to stomach for people who know better.
Yes, western cultures are often mixed up. Just look at every fantasy viking ever existing, that's just a very bland scandinavia mix. And I'm pretty sure every scandinavian is quick to tell you the difference between his and the other countries culture.
Then there is the typical anglo-franco-party mix, that's pretty much just the british isles and france with some fantasy races mixed in.
Or look at the Kurzick, they are germans mixed with slavic and asian influences. Do I, as a german, mind that? No, why would I. It's a fantasy world and they are allowed to take influences from where ever they want and mix them together. These are not actual representations of anyone. That's why the asian community crying over it just shows you two things.
1. Asians, especially the chinese don't like to be depicted in any way that could be seen as bad. Just watch Red Dawn if you don't believe me, the villians were supposed to be chinese, but they had to swap them with North Koreans in post-production, so they could market the film in China. Did europeans ever complain that they are the villians in about 50% of all hollywood action movies? Yes a little, but they didn't threaten to not show the films, because it's not that much of an issue.
The asian community however disliked Cantha, because it had the slums of Kaineng, therefore, all westerners think that "all asian cities are huge slums". They totally overlooked the beauty of Shing-Jea, or the farming area just south of Kaineng. They only focused on the negative, which Tyria and Elona also had (landscapes destroyed by war and hostile deserts respectively).
2. Asians still don't like each other very much. They aren't completely over WW2 yet and the economic power struggle between Japan, China and South Korea certainly doesn't help. They don't like to see their culture being blended together with the others, because they don't like them very much (on average, of course their are people who embrace the others culture, but I wouldn't say it's the norm). I wouldn't call it racism, but it's certainly some form of distrust and disrespect. Again look at Europe, we were the same a century ago, even worse to be honest, but we got over that after 2 horrible wars. We learned the hard way that we have to work together to make a better future. That's why the EU is a freaking great idea, maybe one of the best in recent history, even though people tend to give it very little credit, because the EU made mistakes. The good sides outweigh the bad sides though. Just look how good France and Germany cooperate, 100 years earlier their favorite pastime, was going to war on each other. East asia lacks this sense of unity.
And to clarify, not all asians behave or think like this, however the majority are, atleast in the asian GW community, otherwise this wouldn't be a problem.