Your article is insightful, but I've got to take it with a grain of salt.
Given the timing of the work's publication (immediately after driving out the Mongolian Empire, or Yuan Dynasty, whichever you prefer), I can see an argument for it being written out of bitterness more than anything else (as you suggest) and in fact this would explain a lot: the unusual decision to cast Cao Cao, ruler of the Northern "Wei" kingdom, as a villain for example, fits with the archetype of the "northern barbarians," and by placing emphasis on Liu Bei's ties to the Han Dynasty there is a less-than-subtle racial undertone (the Han vs. the Northern foe).
However, given my experience with the Chinese, I would say that this bitterness was made worse by the fact that their entire society was already built upon a pre-existing sense of superiority. I wrote about this once upon a time, and Stephen W. Mosher (who lived in the Chinese diaspora for 13 years) came to similar conclusions. Simply put, many nations have been conquered and subjugated in history, and have faced the shame of that after driving their conquerors out centuries later (the Persians went through this with the Medes, the Egyptians with the Hyksos, and the Koreans went through this with the Chinese if I'm not mistaken). But for the Chinese, there was an unmistakable sense of "but this time it was us, and this kind of thing is simply not supposed to happen to the 'Great and Glorious Central Nation.' "
In short, I can agree that it was written from shame, but it seems to me that this shame stems more from an arrogant sense of superiority than an inferiority complex.
Anyway, your response was well-written. If you don't mind, I'd like to add a link to it in my original review while it's still fresh enough to edit.