Except that's a critique of the publication rather than pertaining to the content of the article itself, which I don't think is a fair reason to flag a posted article. Posted articles should be evaluated on their own merits.
To address monstrix point though, I don't agree that each publication should be expected to take one side. It really depends on the type of publication and their chosen structure; some publish for the "left" or the "right", while others are willing to publish articles from authors with differing political views. The New Yorker (which I happen to subscribe to) is the latter type of publication - they publish a variety of authors who argue their own viewpoints, generally a great selection of fiction, poetry, and non-fiction.
One additional thought: I think it's a good thinking tool to read well-written opposing views to get inside the mind of one's rhetorical opponent in order to understand an issue from multiple viewpoints when forming opinions and arguments.