I'm no expert, but you missed the part where Peirce was written out of the history of logic entirely for most of the 20th C[0], I guess due to the centrality of Frege/Russell in the Anglo/analytic tradition.
The article doesn't seem to me to claim that "one person fully deserves the credit". "What is the point of that"? I guess to be able to give readers new to Peirce, in a couple of paragraphs, an idea of the breadth and importance of his work. I'm not sure how the article "ultimately demeans the value of its subject", if you mean Peirce. It's not a technical journal article, but a "learn how awesome Peirce was!" article, and begrudging Peirce such articles seems a little, well, more goblyny than queennely.
Thanks for the interesting article!
[0] in English, at least, I mean.