Eh, I don't think that this pattern is even remotely a uniquely Chinese thing; this is just how most people react defensively of the country and narrative they identify with when it is seen as threatened by a hostile country. Look into any Reddit thread on the topic of Russia and Ukraine, and you will see the same patterns play out with Americans giving each other backrubs for the most implausible theories imputing cartoonish evil to their geopolitical opponents (these days I quite often see celebrated posts suggesting that the US should withdraw its military protection from the ungrateful Germans which surely will result in Russia invading them), while accusing every disagreeing poster of being personally on the payroll of the Russian propaganda apparatus.

Of course, the situation in Russian popular forums is not better in the slightest, and the relevant patterns of conspiratorial thinking are reproduced at even the smallest of scales all the time. It has become a bit of a trope on 4chan that some contingent of posters will, if more than one post disagrees with their viewpoint, immediately claim that the two posts were actually made by the same person sockpuppeting; and last time I checked the recurring threads for some video games I play (still among the best sources for real-time information and gossip about updates and what-not...), they were all getting torn apart by mutual accusations of off-site conspiracies (usually on Discord) to push some viewpoint or meme or another.