Unlike “leaving the Methodists”, leaving LDS is more like leaving islam. That is because it is a kinship structure as well as being a system of belief, which itself is thoroughly entwined in kinship: past, preset and future.
It can be done, though; but at great emotional cost.
There is a Joseph Smith quote where he states he is the Mohammed of his day. So considering its scriptures questionable origin at that quote it is an apt comparison.