The lowest value contributions on HN are inevitably those that use a headline to air personal grievances vaguely related to the subject of the post (“Apple releases new cure for diabetes”, top comment: “Let me tell you why I hate the touchbar.”) the second lowest are those that clearly read the headline and ran with it, without reading the content that utterly contradicts what they imagine the article would contain.
Not having read the article / not discussing anything in the darn article should absolutely be grounds for criticism.