Graphical user interfaces are universally considered modern.
They are sometimes related to the principle of information hiding.
Are they even really interfaces? Aren't they just opaque surfaces?
Software interfaces objectify the communication between software entities. GUIs set a sensible barrier which information cannot cross: they implement a mind / matter separation, or rather a software / hardware one. They impose a concrete binding, when software excels in abstraction, and minimal couplings.
All the graphical metaphors are indeed hardware metaphors: desktop, buttons, scroll-bars, maps... GUIs build up appliances for users who hate and fear software!
They implement the anti-thesis to automation: with GUIs, the user becomes a component of the system. GUIs are therefore a reaction (a dialectical step) against the software revolution.
Previous similar steps in this dialectic can be traced to cave paintings, between 45000 and 15000 years BC, to icons in the middle ages, to medieval thetre ('mysteries').