I think most of the workers are basically robots now because their jobs are so mundane. Imagine if the only thing you did all day was check boarding passes and confirm it has the same name as an ID card. Your eyes would glaze over and you would start to think about something else and just go through the motions without even actually doing what you are supposed to be doing. I can only imagine that this is what happened to my friend that ended up on the wrong flight. That and that fact that he is a bit of an idiot.
RE: A really stupid airport rule a friend of mine was recently subjected to