It doesn't just deal with today. Those 25 garbage time snaps would've been very valuable if Nassib got injured while we were holding a slim lead. Instead of a deer in headlights debut, you'd have a player with some experience getting playcalls from the coaches in front of a live (maybe hostile) crowd and running a huddle against a game clock (I'm sure they practice that way, but you'll see less of a mental letdown from the remaining players if someone comes in that they've actually competed with before), not to mention running plays against an unfamiliar defense. Could be the difference between a game-changing series (the bad way) while the new guy gets his feet wet and continuing to run business as usual. [although it would've been IGLQBCL going in instead of Hunt last year, the idea applies going forward.]
That said, I don't see the need to bring in the backup so late in the game that they just run the Victory formation. But if there's enough time that you'll need to run some sort of drive to kill the clock, get the backup some experience. Ideally, we'd have enough faith in QB2 to give him a real series earlier in the game too, maybe running some of the scripted plays to evaluate how the defense adjusts to certain formations (added benefit of having the starter on the sideline discussing what is seen with a coach). That may not have been the case last year though.