how are you going to argue that a good defense doesn't trump a great offense in the playoffs when it just happened in this game?

Look how the Skins held Seattle below their scoring and yardage averages. If the offense had just been decent, Seattle likely would have lost.

Or wait until next week when Carolina beats Seattle (with it's top 5 offense).

A good defense will hold a good offense below average. Pittsburgh's D did it's job... Indy's didn't (and hasn't for years).