If Trubisky doesnt throw away those 2 and the Steelers get FG's, then its 6 points and the Ravens likely play more aggressive in the red zone on other possessions rather than settle for the Tucker FG's.
Its what he needed to do in order to keep the pressure on and keep the game closer. Like if it was 13-13 at half that is great, but the Ravens would just continue to pound the ball on the ground to get the lead and try to manage the game with their 3rd string QB in the game. So when they are up 13-7 and 16-7, it just becomes a coaching process of managing the game with defense and running game.
The game wasnt really as close as the score indicated.