to BYU attendance. These are often the same people who think all Church members are "self righteous" and didn't like the smart kids in grade school because they were "know-it-alls".
Some BYU fans aren't very self-aware in how they talk about BYU as well and I can see where some people would get the impression of arrogance.
For example, I attended both BYU and BYU-Idaho and have therefore been asked many times to share my thoughts on the differences between the two institutions. It is quite difficult to do so honestly and accurately without it coming across the wrong way, especially when the question comes from a BYU-I student or alum.
And then, of course, there are those few BYU grads who are just truly obnoxious and deserve to be beaten with a pool noodle.