It seems like a way to try to express faith amid uncertainty.
Things like..." We don't know why God does what he does, his ways are higher than our ways. But it is always for a purpose."
"We don't know why God told President Hinckley the Hoffman forgeries were real, but it was all part of the plan."
"We don't know why Joseph was commanded to setup a failure bank in Kirtland, but it was necessary."
"We don't know why Joseph thought the mummy scrolls would reveal ancient writings of Abraham and Moses, but they somehow were conduits to revelation and we now have the Pearl of Great Price...literal scripture lost to the world."
"We don't know why Nephi had to chop off a drunk guy's head to get some books, but it is all part of a plan."
God works in mysterious ways. So we tell ourselves, when we don't understand why past prophets said what they said. Or we don't want to just accept prophets and church policies were wrong.
I wonder how many things we will learn when we get to the other side were not of God but we were taught to have faith in it?
I expect God will say...
hey...I didn't do that...you all thought that up on your own.
I just couldn't believe you didn't ask me about it until 1978! What took so long?