> It's disingenuous to say that he abandoned ship because he was mistreated because other people of the same ethnicity were spies? What kind of insane reasoning is that?

It's non-naive reasoning based on the knowledge that yes, people do care about their own race and ethnicity and may have multiple loyalties, and the world doesn't work based on a simple 'you are 100% loyal to the country you are in' bit of reasoning.

Try engaging in less abuse and more probabilistic reasoning.

> Either there are good reasons to believe he was a spy, or there are not.

Either this is a false dichotomy, or it is not.

> If there are, then let's hear what they are, but "other Chinese people were spies" is not remotely a good reason.

Yes, it is. If other Chinese people were spies at above base-rates, then one will be more accurate in finding traitors by taking this into account.

Given that it seems he was quite loyal until he was persecuted by his country, how do you think that reasoning turned out in the end?

> Given that it seems he was quite loyal

Well, it does! The only points to the contrary that I've seen presented so far are that 1) he left the country after being persecuted and prevented from working for years and 2) he was Chinese. Neither are even remotely convincing.