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.
PowerUPP: GUI functional AMD GPU configurator for all voltage configuration, frequency tuning, SoC and memory frequency and voltage tuning
CoreCtrl: GUI usually-functional AMD GPU configurator. Fan curves, over and under clocking, power profiles, frequency and voltage tuning
You have to enable 'amd.ppfeaturemask=0xffffffff' in your boot options, but that is clearly stated in the user guide.
For sound, PAVUcontrol or the KDE volume setting GUI have been able to fix 80%-90% of my audio issues. I haven't used a command line for audio in a long time.
I agree that GUIs make it easier for mass-adoption but things not working out of the box and having to search for solution is just as much of a Windows problem as Linux. If someone has non-standard hardware, it is always a bigger problem to switch to another system. Windows still will randomly shut off my Yeti microphone input and switch to my monitor with no microphone as the system microphone on boot sometimes.
The difference is in windows for weird setups you have to run obscure possible virus runme.msi from 2015 where linux you have to put in an obscure command that you aren't sure what it does from a forum post from 2015. The only one that has mostly nailed that down is OSX.
PowerUPP hasn't appeared in my discovery so far. I'll check that one out. CoreCtrl is the one I'm planning to test so I can't comment yet. Hopefully they also offer more basic feature controls as well.