That is a valid point however I would call it the Cowboys effect, Since the rise of the Cowboys in the 60s all the mediocre teams have given the Cowboys their best. In the years the Cowboys were mediocre as well it mostly resulted in loses, in the years when the Cowboys were good those teams which beat us or even played a very competitive game would say, hey at least we played well against the Cowboys.
I do think many fans have forgotten or are to young to remember those days, but the fact is to many teams beating the Cowboys is as good as it gets. Combine that with a team that has some talent and whose season is on the line like Detroit yesterday and you get the kind of game we all witnessed.
One thing I know for certain is those all out games from opponents are going to get more frequent, I think fans should understand that. We won't be sneaking up on any teams from here on out. And I also think the coaches need to play it as such and leave something in the bag for the playoffs. That's where we need to show everything we have in our playbook not before. IMO blowouts mean nothing until the playoffs start, play to win but keep it conservative is OK with me.