You see this shit SO much more often than you would think. And the infuriating thing is, it seems to be most common among programs that are INCREDIBLY complex and sophisticated.
It'll be like this:
"What does my program do? Glad you asked. It simulates stress patterns in glass and ceramics, after they come out of a kiln. You can specify any melting temperature, adjust the composition of elements in the glass, and the ambient temperature of the cooling and tempering stages."
"Wow, can you show me how it works?"
"Sure! "
"O-oh. Do you have any plans to add a graphical user interface?"
"HAHAHAHAHHA, no. That's never happening. And here I thought you were serious about using advanced software, and being an intelligent person."
Obviously, that last part is just kinda implied. But sometimes, when users request a GUI, the goddamn developer will kinda get in their face, like that.
They always fall back on the position of "well, I developed this shit for free, for your ungrateful ass. So you can build your own fucking GUI."
But the thing about that is...no. And fuck you. I shouldn't have to be two-thirds of a fucking developer, in order to use the fucking software.
If you can figure out how to simulate molecules, or draw 3D stereograms, or translate hieroglyphics, or any other RIDICULOUSLY COMPLICATED SHIT, making a graphical user interface should be nothing to you. You should be able to do it in a fucking afternoon.
IT DEFINITELY SHOULD BE THE EASY PART, FOR YOU.
All the rest of us, who aren't programmers? We envy programmers, and their ability to really connect with computers, on that deep logic level.
If we could do that shit, we would. But a lot of us have tried, and we realize it's not a good use of our time. We can do cool stuff with software, but it's just not ever going to be worthwhile for us to struggle through the act of creating software.
Also, I hasten to add that I have put in my time, using command line interfaces. I used DOS, I used BBS systems, I have used modern command-line-only programs. I know how to do it, but I DON'T WANT TO.
I don't want to have to memorize commands. I don't consider a GUI workflow to be some kind of weird luxury. It has been a basic part of modern software, for around 40 years at this point. Literally get with the program, guys.
If you're serious about making software, get your shit together and implement a fucking GUI from the very first release. Nobody ought to be taking you seriously, if you refuse.
Conversely, I think that every program should have a way to operate it from the command line and the GUI can just needlessly get in the way a lot of the time `¯_(ツ)_/¯
You write a command once and you can do whatever you want with it, repeatably, forever. It's fantastic! You can then pipe the results into a completely different program all without needing to do much of anything! Want to run it on a schedule? Easy! Want to send the exact parameters you used to someone else? Easy! Want to copy and paste the exact output? Easy! Want to get a daily email with the results? Easy!
Some things are better with a GUI, but, plenty don't need it.
With all that said, I understand why a dev who didn't build their program with CLI in mind wouldn't want to go in afterwards and add it in, especially if they don't use/like CLI interfaces.
I've seen similar arguments to yours that every program should have be packaged as an exe, because fuck those fucking programmers thinking I should need to install python to make their shitty programs work. The devs are like "I don't use Windows and wouldn't even know how to package it as an exe and even then, I wouldn't even be able to test that it works, python just works for everyone" and then the guy just continues to go off on a similar rant to yours about how ridiculous this is.
Besides, even if it had a GUI, the complaint would be "why don't they make their software do the things that people want it to do‽‽‽" and then going off about how easy this {insanely complicated thing} would be to add in and EVERYONE {nope, just you} needs this function in order for this software to be useful and the dev is just a POS for not adding it.
Like, I get your point if you're paying for software that doesn't make it clear it doesn't have a GUI, but if you're just on github using someone elses software that they made for themselves and thought other people might like, why are you bitching? Just move on to another piece of software that can do what you want and has a GUI (I'm going to guess you can't/won't because those cost money and you wouldn't be able to belittle and harass the actual software creators and that's half the fun for you).