China shills - who believe that China can do no wrong and the whole world is biased against it - are remarkably common and impervious to facts and logic.
Basically anything that makes China look good is reliable and true, and anything that makes China look bad is unreliable, fake news and a Western conspiracy to put China down. And anyone who says anything negative about China or the Communist Party (no matter what it is) is biased against China.
While one might not be surprised at China Chinese (aka PRCs) being China shills due to socialisation (some might say indoctrination), there's a remarkable number of non-China Chinese who are also on the bandwagon (in Singapore there are quite a few, possibly encouraged by the policy of multiracialism - this does not bode well for the future, as if China ever invades Singapore it will find a ready fifth column).
And while most of them are ethnic Chinese, there're some non-Chinese as well. To find China shills (from China, ethnic Chinese or neither), one could do worse than visit the amazingly delusional Facebook group Xi Jinping - China's Exceptional President, which elevates Xi's personality cult to heights unimaginable outside China.
How might we explain this phenomenon?
One possible explanation is that China shills are part of the 50 cent army, i.e. they are paid to praise the Communist Party of China (CCP). Yet, it is virtually certain that they aren't paid by the Party - if nothing else, they have real jobs which pay better; I used to know one who had several business ventures, for one. It is perhaps more scary that rather than being paid to trot out the party line, they actually sincerely believe it.
A key reason many China shills shill for China is that they are ethnic Chinese (Han).
Chinese Ethnicity and Chinese Nationality are conflated - not least at the CCP's behest, despite its lip service about China's minorities. And since Party, State and Country are similarly and increasingly conflated in China, this means that through transitivity, many ethnic Chinese identify with the Communist Party, especially with China's de facto repudiation of Zhou Enlai's declaration in Bandung that ethnic Chinese should be loyal to the nations in which they lived.
The slippage between the 2 major senses of "Chinese" (ethnicity and nationality), of course, did not start with the CCP; the term 汉奸 (han4 jian1 - literally Han traitor) is attested as far back as the Yuan Dynasty (which was Mongolian), and started to be applied to non-Han traitors in the Qing Dynasty (which ironically was Manchu).
As Rabbi Jonathan Sacks (or one of his guests) points out in Morality in the 21st Century (sadly, I lost track of which episode), the trans issue is particularly fraught because it is about identity. And so it is here, with ethnic Chinese identifying with the Party.
While diasporas having affinity with their ancestral countries is by no means a phenomenon unique to the Chinese, the combination of the sheer size and extent of the Chinese diaspora as well as ethno-nationalism still being fashionable in the Sinosphere (indeed, actively promoted by the CCP) while it has gone out of fashion in others makes China shilling particularly relevant.
Beyond ethnicity, though, one also sees non-Chinese China shills. Barring trans-racialism, ethnic identity cannot be what motivates them. One must look to other causes (which can also explain ethnic Chinese China shilling).
It was suggested to me that Communist solidary was motivating some of the China shilling from tankies (aka Communists, or more formally "an apologist for the violence and crimes against humanity perpetrated by twentieth-century Marxist-Leninist regimes").
Yet, given how openly capitalist China's economy is I don't think this is a good explanation. This is also evident from the rhetoric of China shills, since they don't denounce those who disagree with the Party line as class enemies, bourgeois or Foreign Imperialists. Nor do they justify China's oppression of its own people as smashing dangerous counter-revolutionaries, or say that you need to break some eggs to make an omelette. Instead their strategy is to pretend that China doesn't oppress its own people since it is benevolent, and that allegations that it does are lies, slander and a CIA plot; their defence of the Regime is based on Chinese Nationalist lines rather than Communist ones.
Anti-Western sentiment is a better explanation. This is evident not least since China shills rage so much about how the West wants to put China down, or how Western media is biased against China. Unable to abide by a unipolar world, or even more so one where one civilisation is dominant (as with the End of History), China shills look towards China as an opponent for the West in general (and the US in particular), in response to various grievances (imagined or otherwise). For non-ethnic Chinese China shills (essentially, Westerners) this ties in to their oikophobia (the hatred of or aversion to the familiar. There're parallels here with how Russia, to a lesser extent, also invokes anti-Western sentiment to justify its troublemaking (or pretend that it's not happening).
The motivation of anti-Western sentiment also meshes well with China's rhetoric of a century of national humiliation and the positioning of China as the underdog, with people so insecure and sensitive that everything hurts their feelings and where an orgy is a diplomatic incident - as if a nuclear power with the largest standing army in the world could sensibly be considered an underdog (anti-Japanese sentiment comes into it sometimes too, with the constant dredging up of history to bludgeon people over the head with in the present).
Another explanation is the desire to hitch one's wagon to a star. With the rise of China, more people are motivated to become China shills to vicariously share in its success. In secondary school, I asked a classmate why so many people supported Manchester United. He said people liked champions (or winners). So too is it with China, as can be seen when China shills take pride in China's accomplishments (as if they had anything to do with it). I have been on the Internet for more than 2 decades and the recent swarm of China shills is unprecedented; it is no coincidence that this is correlated with China's rise (social media being more prominent of course makes them more visible, but even in the era of blogs China shills were more or less non-existent).
Yet another motivator for China shills is approval for authoritarianism. China has shown that being authoritarian is no barrier to success, and many China shills tout the merits of authoritarianism while bemoaning the flaws of democracy (while ignoring the downsides of the former and the advantages of the latter). If you believe that people are weak, stupid and/or foolish and need to be controlled since they cannot control themselves, your worldview meshes perfectly with Chinese totalitarianism.
Addendum:
Related:
The Marvelous Simplicity of China Shill Logic
Conflating Nation, Government and Race: China Shills