I too am sometimes frustrated by how HN conversations go. There are numerous times where I know I'm taking a contrary position on HN, and despite my best efforts to present my argument politely and succinctly, the audience seems unable or unwilling to honestly engage with my logic. It's doubly vexing when my comments are downvoted without clear justification. (To be clear: I'm talking only about downvoting, not thwacking from the site admins.)
But I also think there's plenty of evidence that taking a harsh tone in the discussion is unproductive in such conversations, and is ineffective at curbing the behavior of (what I perceive as) unjustified penalization of my comments.
So here's my idea: How about treating this as an intellectual challenge? The goal is to study the form and substance of these contentious discussions, and identify trends regarding successful vs. failed presentations of contrary viewpoints. And then see if adopting those forms results in more satisfying discussions of the points you're trying to raise?
If you're able to nail that skill, especially with a sometimes-fickle audience, you may find it benefits other areas of life as well.