In the many years that I've done software development I've noticed that systems written in-house tend toward two extremes. On one side you have useful software designed for a small quantity of people to do a very specific task, and on the other side you have somewhat clumsy software designed for two thirds of the company to support a wide variety of operations.
The smaller, task-specific software has tens and hundreds of flavors, yet it only survives three or four years until it gets replaced by a new incarnation. The multipurpose clunky software has just one flavor but seems to live for fifteen years, usually well beyond its prime. How come there is no middle ground?
Well just like in animation, sociology creates an "uncanny valley" of in-house software that doesn't comfortably exist. And this is due very much to the nature of people and the work that they do. In most jobs people tend to leverage certain knowledge and skills to support the company with specific tasks. A capable software designer can create very nifty systems that can maintain incredible complexity with the understanding that a moderately competent user will be trained on its use.
Such systems can be local successes even though they don't translate well to other users. And they don't survive for long because they don't incorporate the dynamics of both system-level and human-level changes. People change jobs and don't communicate all of the knowledge. Small systems fall into disuse because they are people and knowledge specific. They are still good for what they are good at: improving local productivity.
Large systems live past their prime for similar sociological reasons. The rate of change in people-skills overwhelms the complexity of linking processes. Linked processes become unlinked, and the training materials don't keep up with the changes in the software.
Large systems still serve a useful purpose however, to the extent that they organize people to work together. Where does the personality of a corporation really exist? In between the modes of small and large software.