Welcome to the 1970s, when IBM published design guidelines that went along with the then-new 3270 terminal, including trying to keep response times very prompt (under a second) to prevent minds from wandering. This was supposed to allow non-technical users to use the full power of customers without having to master a command-line teletype style interface.

GUIs were supposed to the big huge thing that would let non-technical staff use computers without needing to grasp TUIs.