Easy on the man. At least for his last night performance. It's true he's paid to score like Footie said, but sometimes, it's more than just scoring.
I'll give an example here: Del Piero didn't score last night, but because of him we managed to get the foul that lead to our goal(the foul that pissed Mourinho), because of him Samuel almost got sent off and was forced to play calmly to avoid his 2nd yellow card. He calms the play, knows what to do, when to attack when not etc.
Amauri wasn't efficient upfront but he did well defensively and covering back the middle which gives our midfielders extra protection and a bit less work. All this plays a major role in winning games(most of the times).
Plus we don't have full Trezeguet yet and Iaquinta isn't available so lets not complain much right now.