Their prophits and apostles have said so many things, that by keeping the records locked away in BYU archives they can pick and choose what they want their members to think. With so many future (and early on science) theories, they can sift through them and pick the ones that are now known to be correct, are still not disproven, or couldn't be disproven. Its amazing how many bad ones are sitting in BYU archives, but the members don't get to see them. It would appear the leaders don't trust their members to make up their own mind. The trend is unfortunately quite clear.