What is Weis doing? He runs Aldridge and Prince into the line play after play for the last two or three possessions of some of these games. That's essentially telling your team not to score. That Aldridge regularly gets 9 and 10 yards a pop on these plays is just testament to how good he is. Weis is essentially taking a knee.
Running up the score is just shorthand for "continuing to play football." That '96 team was not a great ND team. It was not stacked as some previous Holtz teams were. So why, already out of title contention, were they putting up consecutive 60 point games, including the 62-0 win over Rutgers? The backups weren't "just that good" that they couldn't fail to score, despite themselves. Holtz kept playing.
I'm going to guess the same goes for Knute and Ara and Leahy. Some of these scores are just, people here would apparently be VERY upset about these-
Leahy
55-13 vs Ga Tech
50-0 @ Wisconsin
47-0 vs Illinois
59-6 vs Tulane
46-0 vs Washington
49-6 vs Indiana
Parseghian
69-13 @ Pitt
64-0 vs Duke
51-0 @ USC
56-6 vs Iowa
51-28 @ Iowa
58-8 vs Illinois
56-7 vs Pitt
45-0 @ Army
47-0 vs Navy
51-10 vs Army
56-7 @ Navy
50-7 vs Northwestern
56-7 @ Pitt
62-3 @ Army
48-0 vs Army
And on and on. Note that Ara, one of the classiest, most respected coaches in history, had no problem regularly putting away the service academies by the scores his team SHOULD have beat them by- unlike Weis, who though I like him very much, seems to be very PC about not embarrassing the service academies on the field during war time. Ara had no problems putting 62 on Army, at West Point, during Vietnam.
Calling it a classless move is a modern invention. It's been the move of classy coaches since time out of mind. Your team should score as many as it can. That's why they play the game.