I agree, wj. I also think it's because creationists (at least the fundamentalist Christian types) are programmed to accept authority - no questions asked. Submitting to authority is something that is strongly pushed as a good thing and necessary for being a good Christian. The woman must submit to the man, the man to his pastor, the pastor to a higher church leader, and so on - all of whom must submit to God. It's called faith.
I've seen this same mentality when discussing politics. The fundamentalists do not like to question the president's decisions or his motives and they argue that because he is the president (or whatever), then he knows better than we do.
Questioning authority is frowned upon and it probably has to do with that sort of indoctrination being necessary to take the Bible literally. Or at least follow church leaders without questioning why. In the creation context, if church leaders/elders say that so and so said this about evolution, then it must be true. He's a godly man and wouldn't lie...
I've discussed creation with intelligent creationists, but even after pointing out why quote mining is meaningless and unethical, they still have been unable to grasp why it's wrong. I keep hearing, "But that's what they say right there; it doesn't matter what he says elsewhere."
I think a huge problem is that many people don't have the slightest idea of what evidence is - WILLOWTREE is a perfect example of this.