Do you think it might have anything to do with an absence of posters intentionally trying to make people mad, or throwing around accusations of satanism?
Mainly the first.
Not to make to big a deal of it, but I notice that some of P.Z. Myers' and Dawkins more mawkish anti-Christian sentiment is not too soundly castigated from all sides on DC. There is a certain congruence between the attitude of the mainstream on FR towards some loudmouth posters of a certain proclivity, and that on DC towards loudmouths of the corresponding proclivity.
You can always ignore the most egregious posters on both sides.
Cheers!