I imagine most of us who assume they're faking it make that assumption because the things they're saying are either completely incoherent, as if they literally did not understand what they were saying, or blatantly hypocritical, or at least an argument made in transparently bad faith, as if no one would notice. It all boils down to the same thing -- the inability to believe that a serious, intellectually honest person would say the things these people are saying.
And it's true -- no serious or intellectually honest person would say such ridiculous things with a straight face. Except there's a lot of money involved for the top players of the game; for $25 mil a year, I'd be more than happy to say the things Rush Limbaugh says. I might be inclined to give much of it away just to preserve my conscience, but still, that's a lot of money.
And the amount of money and notoriety in that game helps make sense of the nonsensical, helps provide a rhythm to the bizarre spasms of choir-preaching going on there. That the whole thing might be a marketing gimmick to gull the rubes has more logic than them really not seeing their own self-contradictions and armies of strawmen. It's easier to figure that, say, Jonah Goldberg has a visceral aversion to an honest day's work, than to try to wrap one's brain around the notion that he actually believes what he says, or that he even believes it's intellectually consistent, much less honest.
Most of the inherent entertainment value, at least for me, in trying to parse the opacity of their arguments, is that more often than not, you really can't tell if they mean it or not.