I think the problem is often a little more complex than that. One problem is that the empirical sciences are UNABLE by their nature to choose between competing revelatory claims; coupling that with the superior ability of the sciences to predict everyday phenomena, and the supposition that all religions necessarily grew out of a desire to explain the cosmos, and--bingo--you have the temptation to sweep "all these religious fancies" aside.
And of course, you have other issues such as wishful thinking (on both religious and non-religious sides), intellectual pride, etc.
And if the supernaturalists are right, then you have the factors of real revelation and real deception thrown in--as well as the possibility of all kinds of misunderstandings. (Just try telling one of your elementary school age children to pass a message on to one of their siblings, and you'll see that it really can depend on what the meaning of the word "is" is...)
And all this before the possibility of stories being mangled by history, translation problems, etc.
Full Disclosure: St. Paul came out and said that "now we see as through a glass, darkly." Why do I only find these threads after all the fun, furor and uproar has died down? :-(