Sure, they can talk amongst themselves, but every so often they just have to shoot out a question in the direction of the non-digital world to make sure we're still paying attention to them.
Humanoids can get annoyed about being bothered.
Today's Best of Linux makes both sides happy. Expect steps in and takes the place of someone typing at the keyboard. The programs are pacified, thinking there's someone really there, and the humanoids can be off doing something else. Expect is a tool for communicating with a process which needs input without having to sit and manually enter the input each time. It sits and waits for a string to be passed to it, then sends a string and waits for the next one until the task is complete.