Well, the programmers get blamed more often because, objectively, code error are responsible for more problems than mechanical errors.
But that's not really the programmers' faults. A recurring theme I've heard (and experienced) is that the builders will spend five weeks, six days, and twenty-three hours building the robot, then turn it over to the programmers and say: "alright, now download the code. What do you mean it doesn't work? You had six weeks to work on it!"
Unfortunately it doesn't quite work that way.
