Oh, come on. You don’t think being constantly indoctrinated with the idea that WE are GOOD and THEY are BAD might have had something to do with it?
I think this sort of behavior is sadly very understandable, given that we are taught from childhood that our birth into LDS homes is due to valiant deeds during the time of the war in heaven, in the pre existence. We are better than all other people. We have the truth in all its wonderful fullness.
Then we’re also taught that Catholics going to mass are worshiping the devil, and that they are either stupid people who can’t see the truth that is right in front of them, or they are evil servants of Satan.
I’m sure you and the other Mormons who are (quite inexplicably) posting here will respond with more “I don’t know that we teach that” obfuscation, so I’ll conclude by apologizing to any of the people who were affected by the latest eruption of insanity in Colorado. I hope (as do more Mormons than one might surmise) that our people will grow out of these infantile delusions of superiority someday soon, and I trust that we’ll all eventually come to see one another as brothers and sisters, despite our differences. May that day come soon.