My personal opinion, is that many of these types have only a shallow faith, based on platitudes, fallacious reasoning, and belonging to an identifiable in-group. When anyone with a deeper, more contemplative and dwelled upon faith starts asking questions that they had never even contemplated in their glurge built ingroup-vehicle, the cognitive dissonance is instant and unbearable, hence you get the flurry of fallacious claims and personal attacks along barely tangential vectors. They don't really have an understanding of their faith, and being confronted by those of us that do have a slightly deeper faith, calling on them to go beyond the paint-thin veneer, challenges their uncritically accepted, in group-affirmed, sense of self, and they instinctively lash out.
