Yes, I understand that the quote is from the article in the OP. The point is the quote is about people commenting on the paper. A comment on the article is not

Yes, I understand that the quote is from the article in the OP. The point is the quote is about people commenting on the paper. A comment on the article is not a comment on the paper, and it's entirely reasonable to leave a comment on the article without reading an auxiliary paper that is both not directly available and not relevant to the larger point of the article.