Japanese and Korean pop culture are appreciated in the west because they produce good stuffs
I agree.
I think we should first recognize what is the stereotype towards Asians. It comes with the good and the bad. The good is of course the industrious, smart, law-abiding achievers and not aggressive. This sorta allowed us to get through airports with more ease, less suspected as terrorists, and less chances of getting pulled over for being thought of as criminals. In a sense, we are model minorities. Almost seemed like perks, but then the bad sides are pretty bad too.
On the bad side, we are scapegoats, we steal their jobs, we have small packages(which is false), won't stand up for ourselves, too soft, men are asexual, women are exotic submissive sexual objects for fetish who desires white men, and we don't have eyes. There are more like bad drivers, but they're pretty minor, and it's even funny how this one starts because you never see Asians in car accidents LOL. And then there are the authoritarian parents and Asian nerdy kids who are unsocial. Everything in this paragraph are negative and are false stereotypes.
With all those said, there aren't technically "good" or "bad" Asians. We are all grouped into one geopolitical region, and since most of the racisms towards Asians occurred before recognizing the person's ethnicity, it's less to do with nationality and more to do with simply skin color. With that said, a Japanese or Chinese or Korean will still be called ching-chong right in the beginning. Any racisms that occur after knowing the person's nationalities will still be ignorance, but might be now more nationality-related. And Japanese-Asians are likely to suffer from the bigot's ignorance of the country, mainly sex-related such as Asian fetish or stereotypes from Japanese products such as manga and Hentai. Koreans will suffer from the idiot thinking the person is from the North, and Chinese will mainly be for political reasons. Grasping against Taiwanese, Singapore, and Hong Kong will be slightly harder because there's slightly "less" stereotypes and knowledge about these particular regions, but if you're from a country with its significant nation-culture, then you may suffer from some random ignorance and stereotypes about that country(for example, Thai, Viet)
Usually stereotypes can be changed by more traveling experiences, cross-cultural exchanges and studies, and keeping an open-mind.