You're being downvoted because you're hitting on a trope/cliche that's called out in the rules, and while I doubt HN is dying from a user engagement perspective, I do believe the comments are less filled with value than they have been in the past, given how negativity dang sees conflict.
Healthy conflict is good, but I've participated in healthy conflict here and was stopped by dang because of it.
It's rarely/ever paid off to engage with you on these issues, but if you genuinely do care, I have a 10 year history in which some of my comments have been killed, and in the majority of those comments it's been because of the very existence of disagreement, not because of the nature of how the disagreement was playing out.
It's impossible to say for sure without links, but those comments were probably killed either by user flags or by software, rather than by moderators. We don't typically kill comments outright unless we're banning the account.
As I said, I'm speaking generally. In the absence of links, which you've not provided, I have no idea which posts you're specifically talking about.
Edit: out of curiosity, I looked through your history. All the dead comments back to about 2014 were killed by user flags. Before that, there are a bunch of dead comments but I didn't see signs that moderators had killed them; my guess is that you were banned for a while.
Healthy conflict is good, but I've participated in healthy conflict here and was stopped by dang because of it.