"And those who read the words, and judge what to make of them largely by whether the person identified generally says things that merit consideration."

is incomprehnsible to me. Could you reword it in a way that might help me understand what you are getting at.

It means that random, unidentified comments from multiple people are the equivalent of comments yelled from the peanut gallery. The listener/reader has no way of judging whether that person might be being sarcastic or having a back day or a genius in their obscurity. Or imply yelling things because they like yelling.

It's the same reason why you might choose to listen (or choose not to) to the advice of a long time aquaintence, while not really paying a whole lot of attention to the comments of a random stranger on the street. In the former, you know why they might be making the judgement they are. In the latter, you have no way of knowing if they are even being sincere.