This is an interesting product of the power that automation gives a single person (or few people). If it takes a thousand bank tellers to process a hundred thousand transaction daily, then hundreds of them can leave and things will be fine. Whoever oversees the program can ask people questions when they forget the program details (because the program runs smoothly). If it takes a single programmer's work to do the same thing, you aren't going to put two people on it, but that person will someday leave. I wonder if that alone makes things more brittle.