It is an interesting comment in itself. Does HN ( and other online communities ) have their own peculiar jargon and it is used to identify in-group? I definitely noticed some recurring phrases, but it does not appear to be.. say.. as obvious as 4chan or imgur.

It's less jargon and more tone. Whereas a sarcastically snarky retort might fly on most forums, here it's more likely to net you downvotes. But the same content expressed without the sarcasm will be better-received.