we shared in that just a little more than we currently do.

I think there's some secondary reasons:
A handful of real doofus social media accounts
Carryover from the previous Pac12 conference comparisons
Their cute B1G hubris
The enemy of my friend is my enemy. That window of time where BYU was part of "us" and UU was "them", and I think we did a pretty good job making impressions last year.

But, deep down, I think one of the top reasons is that their football team has put together a reputation that is flat out scarier than ours is/was. I'd be thrilled to add a little more of that intimidation to the nice-guy image that we've cultivated so far.