Why does anybody expect this offense to be better? They let the deep threat go (yeah I know he was a bitch), they put an inexperienced line in front of the QB, and Isaac Redman is the feature back. Even if Bell was healthy, did anyone really think a rookie RB was going to carry the offense?
The Steelers spend most of their money on defense, so don't be shocked that the offense is bad. You want to blame someone, blame the front office for that.