With that being said, the moderation here is very excellent and generally keeps the quality of discussion somewhat high, so I agree with your central thesis.
I also understand that this isn't my site, and that I have no control over the behavior of others on this site. I'm just putting that out there.
A good trick is to go to the comment history, and search until you find the last streak of not dead comments. It's fine to vouch the [dead] comments (if they are fine), and enough vouch unkill the comment. In the case of bopbeepboop it looks like many of the comments were vouched.
How does one do that? Haven't seen any option to do that.
In actuality, even factual and cited posts will get you shadowbanned if your opinion is contrary to the mainstream (on HN) narrative.
I think it’s more “conforming” than “constructive”.