It comes from a constellation of causes: * Most command line programs are FOSS, which means people are scratching their own itch instead of trying to develop a

It comes from a constellation of causes: * Most command line programs are FOSS, which means people are scratching their own itch instead of trying to develop a product intended for consumption by others. * Adding any kind of interactivity increases the complexity of any program, increasing the difficulty of development and maintenance. * People working on the command line often want to call the program from other scripts, which is harder for interactive programs. * Interactivity is not good for composing operations except manually. Non-interactive commands are much more easily composed with each other in sophisticated and customisable pipelines.