Timid and scared play calling on both sides of the ball. You might be able to get away with that against the Jets and Ravens, but you think that's going to work against teams like the Patriots, Lions, and Packers? Anybody see the Broncos-Colts game? The Steelers aren't even playing the same sport.
The Colts originally wanted to establish the run and control the clock against the Broncos. After one drive, they realized that wasn't going to work. They became aggressive on offense and put the pressure back on Manning and the Broncos to come back. Defensively, the Colts jammed the Broncos WRs and forced Manning to move out of the pocket, where he is much less productive. Would the Steelers ever do that? On defense, they generally sit in soft coverage and hope the other team's offense makes a mistake. On offense, the Steelers will waste drives and time trying to establish the run, while the other team scores quickly when they have the ball.
Don't let these past two wins fool you. The Steelers are still playing an outdated style of football.