For example, one of the most counter intuitive explanations for Joseph Smith's taking of multiple wives came first from a Stake President, and then from an Elders Quorum President. They both said, "Well, we don't have many writings from Joseph Smith on the matter, so we don't know why he did it."
In other words, having less information about it somehow strengthens the position. Really? If I were in the position they claim Smith was in - extremely reluctant to engage in polygamy - I would write down everything I could, explaining exactly what was going on, defending and justifying my actions. Instead, Smith hid his "divine" practice as much as he could, even lying about it publicly several times (source).
The fact that he did not journal about it extensively seems to hint toward shame, secrecy, and dishonesty, but certainly not transparency, obedience, and honesty. By all appearances, Smith hoped that no one would ever find out.
A believer may conclude that Smith must have been commanded not to write down the reasons (see Mormon 5:9; D&C 76:115). But then the argument goes back to the question of just how much a prophet should be allowed to hide from his followers.
I, for one, find it very dangerous to assume that the less information we are given, the less concerned we should be.