Comment by supern0va

On the surface, that's quite fair. However, there's one problem: it is much easier to make statements than to verify them, and that asymmetry is part of why the internet has been slowly eroding society.

It's useful/necessary to use past writing/arguments from an author to say whether they should actually receive any further critical evaluation, or be dismissed. We shouldn't say definitively "they're always wrong, so they're wrong now". However, it's reasonable to say: the author has a demonstrated lack of credibility, so we can probably assume they're wrong here, particularly if they have been wrong in this domain so many times before. Or if they happen to be correct, it's probably not strongly demonstrated by their work.