There's also a pretty hard bias in what is considered political and what is not. When I happen to disclose my identity (which is considered very political, apparently), even if it is topical, I roll dice on having that comment be purged to hell no matter the value of the contribution. Depends a bit on the time of day, even.
For example, often HN users need to scold their readers into a hair-splitting debate around semantics.
The other one I’ve seen is pretend-gaslighting-as-begging-the-question:
“Can we all stop pretending that object-oriented programming is an efficient way to build software?”
Edit: That wasn't intended as an insult, in case it can be taken as one.
;)
I tend to agree with you (finding the leading No\n grating when it's used as a "well actually" replacement) but ime its sometimes used by people from cultural backgrounds where the standard for communication is more direct than what the English-speaking world is used to, and not intended to come across as smug or know-it-all, and I don't mind it as much in those cases.
One example: HNers tend to approach topics as if they have a solid grasp on the context of a matter, and are often negative, hence dang's plea against 'middlebrow dismissal.'
Another example: the common practice of leading rebuttals to a comment with "No. \n" While that's OK here, there are a lot of people who would qualify that as "really fucking annoying."
HN culture leaks onto sites that get linked to by it, and fairly enough, not everybody is down with that.