Recent history tells us that the teams that go the distance ALWAYS rank in the top 20 in KenPom's offensive and defensive efficiency ratings (Utah is #18 in offense and #8 in defense), and that they almost always have an NBA PG leading the way (Delon Wright), and I just think Wright is the type of guy that can give teams a lot of issues. There aren't many teams that really have guys that can defend him IMO. And the fact that they shoot over 40% from 3 as a team is an added bonus.
Basically, they play stifling defense, can shoot it from outside, and have a do-everything NBA-bound PG that's capable of putting the team on his shoulders when need be.
Edit: Having said that, with my usual luck with brackets, Stephen Austin will almost certainly beat them in the first round lol (and to be fair, Stephen Austin is a really good 12 seed IMO).