So, no religion is allowed to change, to evolve beyond failings in their doctrine???
Well, considering that polygamy was supposed to be an eternal ordinance- that 'gods' words according to joseph smith and that later prophets allegedly hearing straight from 'god' all reiterated polygamy would continue forever.
Or consider this - this 'evolution' was due to the US Gov't moving in on Utah to put the mormon president in jail along with the rest of the mormon leaders and disenfranchise the church.
Oh, they still have the scripture that 'god' revealed to smith as part of their scripture.