Why would the same not be true of the bias reporting of CNN? Lacks balance

This article is not very nuanced and is not honest about the partisan-led mistakes that publishers on the left make that are just as bad as those that Fox News makes. The author seems hesitant to conclude that MSNBC (or CNN which isn't even mentioned in the piece) might fall victim to the same errors in reporting. What I found especially interesting about this piece, unrelated to its credibility, is that disagreements are emerging amongst the Wikipedia community on which sources should be deemed credible when contributing to their online encyclopedia. If only there was a Wikipedia-esque model to determine the credibility of each article, author, and outlet....I'm sure that would help the Wikipedia editors move forward with their larger mission (cough cough Credder cough cough).