Ok, seriously, I thought about this some more, because I am used to the sneaky way Marian has in slipping in "simple" puzzles for complicated issues.
I went beyond documentation, and its tremendous variation. You see in ms-win-nt (last time I had taken a serious look at MS) you look and read at one piece of documentation and you know what to expect and how all are organized. In **ux/ix you have various sources and styles. People can't even agree whether they all use --help or -h or how man xxxx-software is structured. You read one and say wow, you read another and you are finished with more questions than before you opened it up. The majority of users try to use software without even taking a quick look at documentation, especially before they try it. If you are like me you try it, it fails, you look at options trying to guess the right syntax, it fails again, and then you end up reading a man page just searching for what you want to do not what in totality the software can do. Then some months go by and you think you know it all and it is getting 1-2-3-8 upgrades and you never look again but both the software and docs. have changed. Pacman now is not what pacman was a few years back.
I think it is safe to conclude that quality documents need quality readers. But also quality software can only be respected by very demanding and knowledgeable users. So you have s6 and you have systemd, and by the vast majority systemd is better. I remember when I thought it should be so easy to create an .iso of a system as using dd (like: # dd if=/dev/sdb3 of=~/myarch.iso). Then I realized it wasn't. I was on debian back then and there was a tool (which surprisingly can not be found in Arch) called xorriso (not like in Spanish sausage). The guys that make these tools are geniuses in file system peculiarities and experts in iso-9660. What has stuck in my mind is how complex the subject is and how good the documentation is for those who want to learn the art (
https://www.gnu.org/software/xorriso/man_1_xorriso_devel.html). It was good reading, as opposed to really confusing and boring reading, and pretty effective if you got into it.
So one of the problems we face in linux is that the documentation is inconsistent. There is a difference reading subjects from 3 different volumes of an encyclopedia, and 3 different books on the same subject. Here we have 3 different authors of 3 different subjects. Sometimes inconsistency is just as bad as bad quality. On top of learning something new you have to learn how to read about something new in a new way. I hope we agree. Do you like wikipedia? I think it is one of the largest achievements of humanity since the Gutenberg invention. With a $50 machine you can install obarun and a browser, and a few dvd's of the latest wikipedia and allow people to learn more than they can in a lifetime. I think it is one TB for the English version which is the largest, followed by Spanish (maybe old data, and Chinese has grown).
I mentioned above a hint of the constraints for all this and the fallacy of comparing industrial mass produced tools (of profitability) against one-off pieces of craftsmanship. A Pininfarina prototype with a 67' Chevy Chevelle. The Chevelle is both better documented and much more reliable. I'll take the Pinin-farina with all of its faults and lack of documentation. But back to Gnome documentation and format. Have you thought how really sloppy code, with tons of bugs and possible situations of them causing an error or a crash, can be covered up with a gui? It may evolve into 60% of the code becoming a patch to cover up and deal with bugs and errors. The gui installer (for example) may pop-up a fancy colorful and decorated window saying that "not all software could be installed from the repository at the time, would you like to go back and restart the installation or would you like to continue any way", while the true error messages may be two pages and it is all because the installer doesn't work too well under certain conditions. The documentation may be so fancy that it strikes you as the world's friendliest linux installer. Search around for Calamares, some people will not even try a distribution unless it comes with Calamares. I think it is a turd and when it runs into a fault it doesn't give you a clue of how bad it screwed up. But it sells, meaning "people" like it. It has colors and buttons, and drop menus, and "options". The first time I installed Obarun and got it right, I thought it was so much fun I did it a second time with different options. I couldn't believe that it could be so simple and so direct with as much freedom to choose (I never installed compton ever since). I admit I don't like the latest change of those yes/no half screens as I did the older style. I like it when it runs into an error it exits and tells you exactly why it did and at what point it did. Ok, if you ask me to make an installation really quick now and make sure it boots the first time I would just use pacman, but if you ask me to install slackware I would probably rely on the installer.
Since you compared auto manuals I remember this sad woman, school teacher, whose Citroen was sick, took it to official service and got a diagnosis that was about as much or more as her weekly salary, for a whole new distributor. I heard the car huffing and puffing, I raised the hood, I could almost hear sparks ticking around the cap, and there it was, a hairline crack of the cap. The new cap I put on, about $10, made it run perfect, I threw in a set of cables as they looked fried because she couldn't afford them. She was miserable for days driving around at 40kph burning all this fuel.
The guys at the official service were no crooks, they were young mechanics, following what the school taught them, listened to their duties prescribed by the supervisor and did what they were told. They plugged in the computer at the ECU and the code they got was for a faulty distributor. They weren't lying. If a bug had crawled in and burned up a contact it would still show the same. The instructions at the professional documentation of the official service centers in this 21st century do not have any instructions in rebuilding distributors, only replacing the whole!
Ok, I stop here, I already said too much, it is hard for me to discuss things and not make them a political issue.
I HATE IT when well groomed developers, distro master-designers, deal with a problem a user is having and they recommend to do a reinstallation. There is nothing in linux/unix that can't be fixed. Proposing a re-installation may be just good when you don't have the time for a proper diagnosis and repair. Devs shouldn't make those decisions for the user, who may want to spend the time and learn, but may need a little direction on where to start looking. MS tells people to reinstall because you can't diagnose shit that is all locked up and hidden.
I think the art of diagnosis is similar, car, computer system. bicycle, human. Just machines!