I suspect that's because it drifts rather far afield of the unadorned gospel on which they should focus. Anyway, I'll look into Heiser's offering--thanks for the referral.
Not really.
Humanity and the world (perhaps the universe) is embroiled in a war between Good and evil. The first rule in war is "know thine enemy."
The Bible not only tells us about God and our Salvation, it also teaches us about the enemy of God, the enemy of our Salvation, and the enemy of ourselves.
The preachers I know don't seem to want to deal with the truth about the war we are in. I think they are afraid of the truth...and, frankly, I can't blame them (it is scary stuff).