The 'Mormons' are that group of well-meaning but weird people. Amish get the same thing.
There's a lot of movies/TV shows that purport to show an inside look into these strange and insular cultures. But being a little bit less insualr than the Amish and a little more in the world, we kind of hit the sweet spot.
Weird enough and different enough to make jokes about, but well-known enough to feel comfortable doing so without worrying about it