That is only one on my list of LDS beliefs that make no sense.
When I lived in Central NY we used to get quite a few coming door to door. Several challenged me to read their scriptures and "Doctrines and Covenants." So more years ago than I care to recall I sat down with the BOM and read it cover to cover. I put a post it tab on every historical error and contradiction I found.
The next group that came around I asked them about the errors. No explanation was forth coming. They were very polite, but could not defend their beliefs.
Nothing has changed!
They've all but vanished from FR's religion pages. I ping a few that were active; but they've apparently lost the taste for crow.