I don't see anyone in this thread (or the article) claiming that they're "only conservative", do you?
FTA:
>As the map indicates, there are considerably more conservative-leaning sites than liberal-leaning sites. Only 24 of the 445 sites we’ve identified so far are liberal-leaning.
It's 95% conservative sites. Do you dispute that? I think GP was dead-on in their assessment, skimming or not.