While thinking about this a bit more, I do think there is a difference between Mormons ignoring obvious facts and the general “Christianity is wacky too” feeling. Mormonism makes specific, testable assertions of historical fact. Christianity does too, but these are fairly limited and so far in the past as to be virtually untestable.
To be a Christian, you have to believe a magical man came back from the dead 2,000 years ago. Weird and not physically possible, but a very popular belief. However, to be a Mormon, you have a much more robust set of belief requirements, including, but not limited to:
[ul]
[li]A group of Jews sailed across the ocean and colonized America in 600 BC[/li][li]They had horses[/li][li]They had steel weapons and armor[/li][li]Their skin color changed depending on their righteousness[/li][li]They spoke a variant of Hebrew[/li][li]They are the ancestors of the Native Americans[/li][li]A man from the 1800s could find buried treasure by looking in a stone[/li][li]He could also translate ancient languages by putting this stone in his hat and looking at it[/li][li]That his “translations” happened to deal with then current religious controversies is a coincidence[/li][li]A mummy purchased in Illinois in the 1840s just happened to have a papyrus written by the hand of the prophet Abraham in it[/li][li]The fact that the “translation” of this papyrus has been shown to be completely wrong by modern Egyptology is just a misunderstanding[/li][/ul]
And this is just the tip of the iceberg. As you can see, there is a great deal of quantifiable, testable claims in there that educated people SHOULD be able to analyze.
An important variable in this equation is the restriction of information. Mormons stigmatize any outside information about Mormonism, its beliefs, and its founding as potentially “anti-Mormon propaganda.” If you want to read about the history of Catholicism or Lutheranism, you read a general history book written by a (fairly) impartial academic. There are precious few of these books on Mormonism because it’s just not as popular or interesting a topic. (Also, primary sources are surprisingly scarce.) A Mormon in good standing has had it drilled into him that you simply don’t need any outside sources or books to study Mormonism. The church provides it all. In fact, non-Mormon sources are dangerous to your soul and probably all half-lies concocted by the devil to lead you astray.
It doesn’t help that most academics find Mormonisms claims not worthy of serious study. Why should they bother when 99.99% of people don’t care?
The result is that Mormonism and its founding is a rather murky corner of history, (not least because the Mormon church buys up all the primary documents it can and then controls access to them) and the membership of the church are incurious–or even scared to be curious. It’s easier to just go with the flow.