Maybe because I'm a child of the '80s, but for me, a sequel is a story that follows the previous one, and sometimes if you haven't seen the original, then you don't understand the second one. Like 'Back to the Future 2.' If you haven't seen the first one, you're not going to get anything out of 'Back to the Future 2.'
What is driving the tendency to discount Joseph Smith's revelations is not that they seem less reasonable than those of Moses; it is that the book containing them is so new. When it comes to prophecy, antiquity breeds authenticity. Events in the distant past, we tend to think, occurred in sacred, mythic time.