I am asian, and I've also studied this in depth. I think the best answer is from the fact that migrating to America is really, really difficult if you're oriental asian, and involves a huge commitment of resources and time. In 2016, there were 260,000 Chinese immigrants who filed applications to enter the USA, competing for approximately 25,000 legal spots. This means that the US embassy can afford to allow in only the cream of the crop - the best educated, most successful, and wealthy Chinese are the ones that have the best chances of getting in.
Secondly, there aren't many alternative routes to get into the US from China/Japan/Asia aside from legal ones. They can't exactly smuggle themselves through a few hundred miles of desert along the southern border. Illegal immigration from China is a long, expensive, and extremely dangerous endeavor generally involving extended trips at sea, and most average Chinese people can't afford it, even if they want to come.
So when immigration is limited almost exclusively to legal avenues, and the vast majority of legal immigrants are carefully screened to be the smartest, wealthiest, and most successful applicants from their country... I think it makes perfect sense that they have an easier time assimilating than most and are such a model minority. Chinese immigrants are far more likely to be educated, are far more likely to have insurance, are far more likely to pay their taxes, and are far more likely to avoid trouble with the law than Hispanic or Black minorities.
If the USA shared a border with a particularly poor and lawless part of China, like we do with Mexico, I think we'd have a lot of people hating on illegal Chinese immigrants too as they pour through the border and look for a place to settle down.
tl;dr We have a good time with Asia because we're only allowing Asian yuppies in. The trip from Asia to the shores of America is also much more difficult and expensive, so even their illegal immigrants have to be relatively wealthy in order to afford it. We're having a much worse time with Hispanics because we didn't get to pick and choose only their well-educated, successful elite. Both their poorest refugees and their most dangerous criminals have a fairly easy time moving over the US border - the border patrol can't be everywhere at once, and there are hundreds of miles of desert to cover.