I'm not sure what you'd like to see changed in this case?
Ideally, when someone claims that they can tell how smart someone is from how they look, that should be downvoted to oblivion and receive overwhelming counter-evidence or no attention at all.
Of course, what happened was quite OK, and much better than many other corners of the internet. But still, it's proof that that there is some explicit racism on HN, not just people not caring about others.
What does this have to do with doing something about the Iranian regime or Chinese regime or any other regime? I barely even discussed homophobia.
And note that you can be anti-fundamentalist without being anti religion, and you can be against the Chinese regime without being anti Chinese people (just like you can be anti Israel without being antisemitic).
I've also seen anti-religious sentiments and anti-chinese nationalism popping up pretty proeminintely every now and again. Climate change denial is also rarely missing from any longer conversation about climate.
Edit: Here's an example that eventually got flagged, but sparked a long conversation that had a few supporters as well: https://news.ycombinator.com/item?id=26990070