Yes, I used plenty of command line on my P.E.T., and my C64, and my 8088 machines. I've also loaded programs from analog audio cassettes. That shit is over. There is no logical, practical reason to use command line. It requires memorization, perfect syntax, and a pre-existing knowledge of all the program's commands (or a lot of alt-tabing) since discovering features is...pretty much totally impossible. In a GUI-based app you can find stuff by just poking around, in a command line app...well, I suppose you could find stuff by just randomly typing stuff into it, but I don't see how.
You really can't do much with a command line anyway since its a one dimensional input scheme. Computer's do great things for us these days. They are used to plan a shuttle mission for NASA, edit a photo, remove cancer with lasers, monitor a cars engine performance, create music, blah blah blah, and honestly using a command line for any of that stuff is pretty much impossible, or at least so impractical as to be never achieved.
I know people who champion the command line interface. I also know people who collect guns, and lift a lot of weights. Both of these people complain about this "generation", and honestly they are the real zealots. I'm not trying to prove anything, I'm just trying to get work/play done on a computer and if I can do it by clicking on a box, rather than searching for some shit to type into a box, that's the way its going to be done.
Now that I think about it, the reason so many underground apps use a command line is obvious; the authors of such programs are championing a dead cause in the only way they know how. I mean, you just can't do anything like Photoshop with a command line. Its just impossible. However, it is possible to run vintage ROMs that way, so they neuter their programs to prove what spoiled zealots we are. Its a shame because I really would like to try Mednafen, but after f*cking with it for 40 minutes or so I just gave up.