That's not even close to true—not by orders of magnitude. This seems like a classic of the notice-dislike bias (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...): that is, you've seen things that you didn't like in one discussion and weighted it more heavily than everything else, including the by-far-most-discussed theme of the last month.
That bias is so powerful that I'm not sure I've seen even a single counterexample, and it seems to make objective assessment impossible. I don't know what to do about it. We can't remove everything that somebody dislikes—there would be nothing left—but the presence of material that people dislike makes them draw extremely distorted conclusions. I believe this is an outcome of HN being a non-siloed site. Most other places on the internet, you choose your silo so you're surrounded by friendly views and don't encounter so many nasty things. Here, everyone's in one silo and it creates a shock experience. This leads people to dramatically false conclusions, but it doesn't matter because they feel intensely true. I wrote about this recently here: https://news.ycombinator.com/item?id=23308098.
Everywhere, including HN.
I do not mind, the tech scene is understandibly americanized but telling that the discussions are hidden is simply not true.
(to be clear, I am just piggy backing on your quote to not repeat it, I agree with what you say)