I see it as arrogance on the part of Levy and company.
It says, "I am going to make them play my game...force them to do what I want them to do."
NFL does not reward such arrogance anymore. The best teams prepare for what you did during the regular season. You have to fool, outsmart your opponent today.
You all would find it very interesting that I said before the Denver-Pittsburgh game (and I have two people to prove it was BEFORE THE GAME), the team that runs the ball the first two plays from scrimmage would LOSE.
Both were top NFL running and run first offenses.
Pittsburgh THREW its first TWO plays, Denver RAN its first THREE plays. Who won? Pittsburgh. Nuff said.
In this game, Shanahan fell victim to the "I will exert my freaking will upon these Pittsburgh guys!"
I don't think it's arrogance, I've seen the interview where Marv uttered the immortal "like any other game" line (I doubt Marv invented the idea, he was just the first guy caught on tape admitting it). Basically his idea seemed to be to avoid stressing out his players and staff, we've all seen teams have problems with the stress of the playoffs and Super Bowl (just last night in fact, both offenses seriously suffered from "OMG I'm in the SB"), and instead the Levy method is to say you're a good team, you were good enough to get here and that should be good enough to win here. The problem comes in when you run into a coach that knows how to amp up the planning without inducing stress.
I'm not sure Shanahan had much of a choice, while the rest of the world was signing Plummer's praises Shanahan saw Jake every day in practice, nobody knew better than Shanahan if Jake the Mistake was really gone or just on hiatus, and I think game planned accordingly. I mean we saw what happened once the Broncs were down by more than one score, Jake couldn't win the game on his own they had to get the run game going and trust their defense to get some stops. Neither happened, they needed Jake, and Jake the Mistake came back.