FIFY.
I was brought up as non-devout CofE, but interestingly enough, those fairy stories still feel less ridiculous to me than those of other religions, although there is no rational, non-emotional reason for me to think so compared to many other religions.
Actually, given how obviously Mormonism is modelled on Christianity, its claims are more ridiculous. Similarly for spiritualism or Jehovah's Witnesses.
The bold part shows the depth of manipulation, or whatever you want to call it, that religion can accomplish when it dominates a culture, and as I've posted elsewhere on this thread, mainstream religions in the US, at least, use it to divide and conquer.
When Protestants and to some extent nowadays Catholics dominate society as the "normal" religion(s), they can convince people that what they believe is the default, while every smaller demographic is too weird and strange.
So the atheists, for example, who ally with Protestants in thinking that Mormons are
more weird, are helping support the very same culture which Protestants use as a weapon against atheists. And the same is true for every other non-mainstream segment.
The arguments are eerily similar: Mormons aren't really Christian because they've added to the Bible, so they can't be trusted. Atheists don't believe in the Bible, so they have no morals. Wiccans aren't Christian and the Bible warns us about them. Etc. etc.
Gradually, other demographics such as Catholics can get accepted by the U.S. mainstream, but only if Protestants feel that they're not a danger to Protestantism.