justify in my mind hanging around for an indeterminate amount of time just to watch the backup QB hand off to the backup RB for a drive or two.
I'll stick around for the end of a blowout, but if there's going to be that extra 30-60 minutes (or more) of no football first, then I'll consider leaving.
Other than that, I'm there to watch a football game, so I'm going to stick around and watch the football game until it's over.