I think you've hit the nail on the head. This same problem applies to many of the internet-based forums where people review movies, dogs, or radios. Its the same question of "can an average joe actually critique a movie?" to which serious critics would say no....but to most "average joes," the critical analysis done on lots of movies serves them no good.
So while people here can give their views and opinions, no one can give an authentic critique without the knife in their hand and a semi-scholarly look into the knife's conception, design, and creation. The question is: Even if we did have a scholarly critique of the knife, would the average member of this forum be able to appreciate it? Or more specifically, would the average forum member benefit from a scholarly critique vs something they can relate to?
I guess its who the thread is intended to help....if its the maker, a scholarly critique would surely benefit them, but might be hard to swallow and I anticipate most discussions would be arguments over intent vs final design. If the thread is intended to expose users to a unique and interesting knife with a cool history and function, I don't think a scholarly critique serves the intent of the post.
Perhaps all this talk shouldnt be on the critique that is given, but on makers being more specific about what their intent was in creating the knife AND by posting the picture.