It is not like the Steelers (or their fans) to look for excuses, and the Patriots definitely showed us that this defense shouldn't even be compared to the 2008 and 1976 ones. However, seriously, I don't think there was anybody who did not expect or fear the possibility of such a beatdown.
Think about the state of the Steelers - in a very physical meaning of the word "state". Out of 8 starting linement (offense and defense), 5 were out with injuries. They say that games are won and lost in the trenches, at the line of scrimmage. Could you really expect better numbers from Ben when his blind side was all but naked? Same for the D-line. This is not to say that the Pats rushed to victory, but they were able to establish the run just to the extent sufficient for the Brady play-action to be effective.
Hines Ward - needless to say, this game showed how valuable this guy is for the team. 3 endzone passes that were dropped (ARE, Mike Wallace and Heath Miller) and another one when Sanders ran the wrong route would have gone to Ward.
There you have it - 8 starters out with injuries or banged up - that's exactly 1/3 of the starters (defense+offense).
Throw in two weak links that have been weak throughout the entire season - the secondary and Jeff Reed. CB's are just not there, Polamalu has been sub-par ever since Week 3. And Jeff Reed... Well, this morning I for the first time considered the possibility of him being cut from the team (something I never thought I would think). Is that his beard that makes him struggle so badly?
The Steelers must bounce back, and they must do so convincingly. Oakland may be a dangerous trap game, just like it was last season, but the next two opponents (Raiders and Buffalo) are very beatable. If the Steelers are 8-3 coming up to the showdown with Baltimore, nobody will remember this game.