Ok so let me guess this straight, and by all means please feel free to correct me if I'm wrong.
Isaac Redman is better between the 20's and Rashard Mendnehall is better at the goal line. With your starting Center out of the game and a totally inept replacement at LG you decide to run 4 straight plays to the right with a guy who's not your short yardage specialist? That about cover it? Oh wait, it's Isaac Redman that's better in the redzone, no wait that's not it. Oh screw it, let's just run it and not take the sure 3 points in a close game with our QB who can barely walk. Ben audibles to a run on 3rd down which results in nothing.
The Browns are selling out to stop the run; crashing the line with literally every defender on the field. Meanwhile you could have had a back or TE release in the flat for an easy TD pass.
That about cover it?
In that situation, Tomlin said in his post game press conference that he would do it again in that same situation. Now, I get the whole mentality of stepping on their throat, ripping their hearts, and breaking their will. If you have 4 shots at the 2 yd. line you should be able to score a TD. Yes I get that, but there's no shame in kicking a FG and getting a sure 3 points to get yourself up by a full TD in a close game where turnovers are plentiful.
After all that I would have kicked the FG and taken my chances with the defense holding onto the win. In the end it worked out because the Steelers defense held and got the ball back for the offense, who promptly took the punt at the Browns 36 and did nothing with it. Maybe it worked out, maybe it didn't, but it's a win.