The fact that this arguable, but clearly reasoned and expressed comment is now deep gray kinda puts an exclamation point on the argument, I'd say.
(Honestly I think the moderation paradigm at HN has some bad externalities too, but really this isn't a solvable problem in the general case and nowhere does it well. The showdead mechanism at least makes the censorship visible to those who know where to look.)
It does. And it's completely understandable why, from a game theory point of view.
The censors want Hacker News to keep its reputation as a place where you can have debates in good faith, while allowing their censorship powers to shape the conversation.
Pointing this behavior out upsets the calculus by warning their potential marks. So of course they want to strategically hide it.