Well, to me that read as "the sarcasm represents either intentional slanting of the meaning, or the author's bias emerging unconsciously." An author doesn't have to write a total polemic to do either of those things. In fact a rhetorical attack is likely to be more effective if it's framed as not being all-out hostile—which in fact seems to be your interpretation of Correia's approach, so I don't know why you would think no one could be doing it from the other side.