Two UIs will cost twice as much to design and build, but frankly, we have stdout and stderr today, you just don't see most GUI application developers making use

Two UIs will cost twice as much to design and build, but frankly, we have stdout and stderr today, you just don't see most GUI application developers making use of them. As a developer/power user, if you let me configure your app with a dotfile that I can keep in my git repo, and you spit out useful info via stdout/stderr when I run your app via the terminal... in many use cases I'm happy as a clam to be honest. In fact one reason I tend to gravitate toward open source apps is because they tend to be more likely to do this, what with their users often also being their developers.