Considering Scott's interest in things kabbalistic (e.g. Unsong), and his general erudition, I suspect he knows more about the origins of Moloch than you give him credit for.
So by calling Moloch a demon, you are participating in perpetuating a potentially false history of Moloch that is heavily biased and Judeocentric. Sure you can call him an evil pagan god, but to call him a demon requires fitting that into a prior belief system of evil supernatural entities which is inconsistent with the very belief system he came from.