Because actually the laws of thermodynamics are only applicable to isolated systems. "The second law of thermodynamics states that the total entropy of an isola

Because actually the laws of thermodynamics are only applicable to isolated systems. "The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time." But usually you can build quasi-isolated systems and minimize the external interference so it is negligible (i.e. a car engine). This is hardly the case of software systems though.