where BYU for decades...and later Utah...were substantially superior to the competition and could win most games. Even with backups.
Back then, non BCS had to go undefeated to be taken seriously.
BYU fans still have this mindset now that only good teams go undefeated. P5 changes that.
Unless a program have markedly superior talent than the conference, it's impossible to win 4-5 road games, all OOC games and a CCG without blemish.
2-3 losses are expected for all but the elite programs.