I don't know that it was because of the low score. I mean, how many people just didn't turn on the game, at all? That has no bearing on people tuning out because of score. If you never tune in, you don't know what the score was or what kind of game it turned into because you never had any interest in watching it at all.
This might be more of a statement on what fans think of the state of the NFL today. I think the officiating and the rules changes might be affecting viewership more then some may think.