"software which demotes overheated discussions" is pretty noticeable. It seems as soon as a story gets more comments than it has points, it drops like a rock from the front page.
IMO this is by far one of the best features of HN - discussion quality tends to nosedive on such threads, or more accurately, be buried under unrelated (frequently political, emotionally-charged, and/or low-effort) comments.
I dont understand HN ranking at all.
At the time of writing Apple's earnings sits at #10 with 45 points (36 comments) and this one sits at #6 with 20 points (3 comments).