People are capable on judging an argument on its own merits. After all, if you don't think HN readers possess that capability, why bother associating with the commentariat on this website?
For the few that might it is generally worth knowing whether it's actually worth the time. If the writer is someone considered and knowledgeable, on a credible venue, for instance. I know nothing about this site/writer so I'm not commenting on that, but generally that is an input before one spends the time on an essay.
For example the best published scientific studies can't be judged on their own merits because you have to trust that the scientists actually conducted the studies and didn't fake the data. So you basically have to fall back to some assumption over whether the scientist is honest, not on the merits of what they wrote in the study.