I also think that your analysis is reductive. Liquid Glass has some serious usability regressions, so there are very good reasons to criticize it, not just so-called "hate". In any case, there have been plenty of good, informative posts about Liquid Glass and iOS 26 in general; this submission, however, is not one of them.
Hacker News truly has a large number of topics for which the reactions and responses are reflexively negative and large in magnitude (there are similar positive reactions as well!). This isn't "reductive" analysis and you didn't understand what I said if your point is "your analysis is reductive because liquid glass has some serious usability regressions". You can even look in my own post history to see that I agree with that just fine.
Still, look through the discussion! Much of it is clearly reflexive negativity and based on zero user experience.
It's entirely expected and unsurprising that Apple's announcement of a major macOS release would receive a ton of upvotes, regardless of how people feel about the release. That's why I think your analogy is irrelevant.
A low quality submission should not receive many upvotes, and as a consequence, it should not receive many comments of any kind, positive or negative, because it won't appear on the front page of HN for people to notice and comment on it.
I think the idea that one behavior being used as evidence for another behavior is problematic is ridiculous.
Just take a look at the MacOS Tahoe topic (https://news.ycombinator.com/item?id=45252378). A HUGE portion of the comments are clearly from people who both (A) don't use MacOS and/or (B) haven't used Tahoe and they are all intensely negative.
Taking Hacker News as an inverse signal on these things makes sense. For example, HN's iPhone Air hate is making me extremely bullish on its sales prospects.