While I'm also often annoyed by global negativity on HN (which, to be fair, has greatly improved lately, way to go guys!), I didn't read parent comment as aggressive, but like if "ummmm no" meant "wait, let me think about it for a sec... no, I don't think so", like you mention in your edit.

But now, this user has been heavily downvoted, which is aggressive, without any doubt. I really wish downvote features were out of the web, this is just group bullying. Upvoting is plenty enough to make good contributions raise above the others.