My feeling is that the only reason HN doesn't have a guideline rule forbidding cites to "Upton's Law" is that there isn't space for it. It's tired, snarky, provides no insight, and never takes the conversation in any interesting direction.

The comment you're replying to observes that a bunch of researchers say that the fraudulent paper simply isn't that important in the field. You can contest that claim! Maybe they're totally wrong! But you can't do so with Upton Sinclair, because Upton knows nothing at all about how Alzheimers research works, and when you deploy that quote, you give the strong impression that you don't either.