Printing teletypes were the next stage of computing after punched cards and printers, refocus-sing interaction to defer to the user, rather than forcing the user to defer to the mainframe. Finally, the mainframe appeared to await the user's every command, providing vastly decreased latency, improved development time, and most importantly, a whole new style of interaction.
In the teletype paradigm, the command/response cycle between user and computer was decreased to intervals of seconds rather than minutes, hours, or days. Complex, monolithic batch jobs could be broken down into smaller, simpler interactions, enabling tighter discretionary control of jobs by users. In this environment, files and line editors flourished and replaced the task of manually editing card decks. Interactive programs and games were developed. Tons of paper were consumed playing SpaceWar on Digital Electronics mainframes. The priesthood was removed from the human/computer interface, and the result to the users was like an emancipation.
Compatibility with the older metaphor was still retained in some cases. Some teletype drivers were mere wrappers around the older cardreader drives, simply making each line of typed input into a virtual Hollerith card. Similarly, sending output to a teletype was little different from sending it to a printer. Older applications dependent on cards could often be used transparently from the new teletypes, preserving the time and money already invested into such legacy software -- at the cost keeping cards' eighty (80) column line-length limit, still in evidence decades later.