Here's why they aren't:
If you were baptized in one Christian denomination and wish to convert to another, you don't need to be rebaptized. Churches will accept the other denom's baptism as a valid Christian baptism. However no Christian denomination accepts Mormon baptisms as valid. Any Mormon wishing to convert to the ELCA would have to be rebaptized. Any baptized Catholic, Methodist, Baptist, etc. would not. Furthermore anyone wishing to convert to Mormonism who was baptized in a Christian denomination would have to be rebaptized as well.
Is that the definition of Christianity? Everyone has to use the Visa of baptisms? Because Mormons require American Express they are no longer Christian?