Ben Roethlisberger cost the Steelers the game. As did Bruce Arians, but then that's nothing new. Two critical, horribly thrown interceptions on their side of the field set the Colts up for more than half of their points, at least the ones not set up by tipped balls by Ike Taylor.
Arians is fine for putting together an opening scoring drive, which the Steelers parlayed again for an early lead. The Colts got some lucky breaks, but the Steelers were able to temporarily pull away. Playing it smart, the Steelers at worst would have allowed the Colts to cut the lead to 17-10 going into the break, but Arians ran a maddening slant pattern on a 3rd and 2 from inside their 20. There was no way the play was to be completed, even if the pass wasn't darted directly to Keiwan Ratliff.
Granted, minus the cadre of players that included Heath Miller, LaMarr Woodley and Bryant McFadden, the schemes were altered as they have been all year with the high frequency of injuries. James Harrison still got good pressure without his partner on the opposite side of the defense. It's curious how many times Harrison is clearly held any given game, with the lineman never flagged, meanwhile Max Starks is called out by referees at the first opportunity to stall a Steelers drive.
Ben has one touchdown and eight interceptions in the last four games. It stands to reason he is injured to the point that it affects his game or that he is going through a slump that requires more than empty pledges to get better. Ben was not overly pressured by the Colts front seven. This wasn't like against the Giants or Eagles. Those were forced passes into coverage. The defense wasnt playing the shutdown game it did against Washington, but it didn't need the added burden of short fields against a superstar quarterback.
To be fair, it's an offensive-wide deficiency that is enabling teams to play tight on the Steelers. With a shitty line and receivers who aren't great at breaking free deep in a hurry, defenses can afford to create pressure before needlessly complex routes develop. At least with Leftwich, the team has a quarterback with an arm not compromised by a hurt shoulder and Arians knows not to design plays that take forever to develop. It change won't happen, of course, which is why the the team has to hope everyone gets healthy soon enough to staunch the bleeding.