I agree Arch should not be used for mission critical stuff.
I have been in situations similar to yours. I run Arch, and I've had to deal with printers (and more exotic hardware) under urgency, I've had to connect to weird WiFi networks where the network admin was some guy who knew only how to click buttons and take screenshots, and I've absolutely had to figure out how to do things from a cli without internet access.
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About the printing business: if you know you don't have something set up in Arch, and you know it will probably take a while to do it, and you don't want to spend that time ... you should definitely use something else for it while you can. This is without all the caveats of the general business of getting printers set-up and running on any OS.
About the intern: why would you even ask an intern to set up and use Arch when all they needed was a working Linux distro? That's just using the wrong tool for the job. It's almost like asking an intern to learn how to drive simply to travel to office every day.
About the network auth:
1. The GUI tool you used was the same as on every Linux distro: NetworkManager (or a NetworkManager client by you DE, like KDE does).
2. If it was WPA2 Personal, you'd have just a password. If it was WPA2 Enterprise, you'd definitely have something more than just a password; and enterprise Wi-Fi is convoluted enough that it requires detailed steps even on Windows 7. The NetworkManager GUI never asks for a username when WPA2 Personal is selected (because that wouldn't make sense).
About your last issue:
1. NetworkManager is the network management software all Linux distros use with GUI.
2. NetworkManager now has a cli, but perhaps that wasn't the case then.
3. It is always wise for a system administrator to know their tools; or at the least, how to use their tools. `wpa_supplicant`'s manpages could have told you what to do when you couldn't reach Arch Wiki.
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And yes, Arch is a system that needs an admin to manage it. That is how it's designed and built. Look at the second entry in the official FAQ: https://wiki.archlinux.org/index.php/Frequently_asked_questi...
I'd pre-configured my Arch system for the day when I'd need to connect a printer to it. And when I needed it and I connected it and it worked, it worked. When it didn't, and it was urgent, I asked someone else to print using their system. This is a common scenario with Windows 7 too.
When a network posed me troubles, I have always debugged it and solved it.
When I needed to figure out how to do something on the cli without internet, I relied on the manpages and the `--help` outputs and my sysadmin knowledge in general.
And I'm okay with that, because it gives me the freedom to have my system my way and because I can do that.
When I'm asked by someone to pick a distro for them, if they do not want to manage their system to such low levels, I recommend Ubuntu. It's just a matter of picking the right tool for the job.