Jews and Christian have however been careful to define what is commonly more reasonable to belief. Maybe to declare it the infallible word of God has been upping the stakes dishonestly and hence the criticism.
But its good that the categories of Midrash and Apocrypha have been allocated for spurious works. The LDS scriptures however are not in the same category where centuries later the authorship remained dubious. Here we have a strong case of deliberate historical fraud by the author to borrow credibility for his revelations, regardless of whether or not he had genuine visionary experiences and inspirational insights.
Banned From the Bible - Documentary http://www.youtube.com/watch?v=nuVKZCb9N4o
Apocalyptic Cults http://www.youtube.com/watch?v=aU3_DkpWDak