Briefly from wikipedia,
Systems theory is the interdisciplinary study of systems, i.e. cohesive groups of interrelated, interdependent components that can be natural or human-made. Every system has causal boundaries, is influenced by its context, defined by its structure, function and role, and expressed through its relations with other systems. A system is "more than the sum of its parts" by expressing synergy or emergent behavior.
In early math courses, we are often taught how to solve mathematics provided models of a scenario, but never quite how theories on how to come with models. The stuff one finds in even the earliest conception of this theory in General System theory, Ludwig von Bertalanffy seems to be quite useful in providing an understanding for this.
Yet, his name or the idea of system theory in general theory is never mentioned Mathematics classes. Hence, my question, how did the system theory as a field fall out of public view?