Let me expand on this thermodynamical metaphor. Open systems that may exchange matter and/or energy with their environment, can maintain or even decrease their own entropy. This is how living organisms exist, without violating the second law of thermodynamics.

If you see a software system as a living organism, then the natural entropy increase (new feature requests?) may be contained if enough energy (developer time?) is invested. Of course this kind of investment may contravene some other commercial software law, like being profitable.