My experience with hacker news is that comments with China mentioned in a not so positive way will result in a flood of initial downvotes. As to the the why, I haven't a clue
My observation is that on certain topics, HN votes and comments become largely based on ideological stances rather than objective reality.
Take this thread for example: "the culture that creates new tech is something that china can't steal and it can't replicate it without giving up authoritarian rule"
This truism that China "can't innovate" because they live under an authoritarian government is very commonly believed on HN, but it's nothing more than an opinion. However, if you were to suggest to these same people that China is a poor source for sourcing immigrants, because <some unique characteristic of China>, the logical parts of their brains would fire into action and point out how "wrong" that statement is, for obvious reasons.
A lot of people, including people on HN, passionately believe things that are absolutely contradictory, and they vote accordingly.
