that tough or not, everyone in college football hears Notre Dame playing xxxxx (and it could be Ohio State or Alabama) and those same people whether they know if Notre Dame has a good team or not, they think "that'll be a good game!".
BYU hasn't won enough games consistently against the P5 teams to have people thinking that. Even for all the history, BYU is still looked at as 'the little school that could in 1984', not as the independent of the west