I've seen teams win 56-0 and not run up the score.
The TD was totally unnecessary. 45-17 with 18 seconds left. Ball on the Husker 2-yd line. Take a knee or spike the ball. Game over. Day wanted the points for the CFP. Can't say I blame him because that is what the game has become. I certainly don't feel sorry for Nebraska as they have been on the winning end many times.