Not everything actually requires a GUI, obviously. But anything that requires configuration, especially for controlling a hardware device, should have a fully functional GUI. I know Linux is all about being in control, and users should not be afraid to use the command line, but if you have to learn another bespoke command syntax and the location and structure of the related configuration files just to get something basic to work then the developer has frankly half arsed it. Developers need to provide GUI's so that their software can be used by as many people as possible. GUI's use a common language that everyone understands (is something on or off, what numeric values are allowed, what do the options mean).
Every 12 to 18 months I make an effort to switch to Linux. Right now I'm using Archlinux, and it has been a successful trip so far, except my audio is screwed, I can't use my capture card at all, I had issues with my dual displays at the start, and the is no easy way to configure my AMD graphics card for over clocking or well anything basic at all.
I'm not looking for a windows clone, I love that I can choose different desktop environments and theme many of them to death. I even like the fact there are so many distros. Choice is a big part of linux, but there is clearly a desire to get more people moving away from Windows and until that path is 95% seamless most people just won't. Right now I think Linux is 75% to 85% seamless depending on the use case and distro but adding more GUI front ends would, imho, push that well into the 90% zone.
GUI is not a dirty word, it is what makes using a new OS possible for more people.
EDIT: Good conversation all. This is genuinely not intended to be a troll post, I just feel it is good to share experiences especially on the frustations that arise from move between OSes.
Wrong.
Lots of tools in Linux have GUI. I can configure my WM (cinnamon), browser, terminal emulator, music player, communicators, email client, network and many more using a GUI.
What I can't configure using GUI are the truly powerful tools: awesome wm, nvim, ranger, kitty. Why? Because you can extend them by writing custom code (mainly in lua). Why would you build GUI for writing lua code in every tool? Doesn't make sense.
Sometimes there is so much configuration options a GUI would scare most users. Or as you said, a GUI may not be feasible or useful
Or if it didn't, it would be because the dev limited the options displayed so much that it would cease to be useful for most users. (This is especially true when different users are likely to use different subsets of options rather than having the majority of them using the same subset.)
YaST in a nutshell...
Takes a whole bunch of system command line stuff (and even stuff already in other GUIs) and throws it into a Windows-like control panel type thing.
Now, it's great that it's an option.
What's not great is opening it and seeing dozens of fucking options, not knowing what half of them are if you're new to Linux. (To be honest, it's even overwhelming if you are familiar with Linux.)
So the people it's supposed to appeal to end up with a complicated control panel they don't understand, and the people who actually know what all the entries are for end up sticking with the terminal and ignoring it altogether.
Although, all things being fair, no one new to Windows would really understand the control panel either, but at least it's so widely used that any instructions you get about it usually won't have you going into the registry or cmd.exe or PowerShell or something.
On Linux and using YaST? Here's the response you'll usually get: "Okay, so click the exit button and look for something called 'Konsole' or 'Terminal' in your applications. Open that up and paste this command..."
The pasting of random commands is something wikis should avoid. The best option is saying the command and then explining what everything does but this is something that happens pretty rarely