One of the things that has struck me with getting used to i3, even after a decade and a half "faking it" by mostly running apps maximized anyway, is that it is changing my thinking, not least due to the API. E.g. I recently started writing a text editor (because, why not), and it struck me that I really don't have a reason to support multiple windows. I added "splitting buffers" today by having it exec i3-msg to start another copy of itself.

I think what is really hampering Linux on the desktop is trying to play catch-up with Windows and OS X instead of rethinking the processes.

I suspect you'd have been better off switching them to ChromeOS. Most people do not need a desktop in 2017. There was only a brief window in the late 90s and early aughties when "most" people did, but that was only because of the internet. We have better consumer-oriented devices for that now. Desktops are for people who do work, hobbyists, developers, and the kind of gamer who is basically the hotrod-guy of the computing world. If someone actually wants to make the Linux Desktop a good desktop OS, they'll have to stop trying to make things "easy" for the strawman of the "average" user and instead make something for those people.

And the thing with ChromeOS and Android, is that having Linux as a kernel, it is just an implementation detail.

Given their managed userspace, Google can switch to something else and only OEMs would notice.

While I largely agree with your observation, the problem with ChromeOS is that not everybody wants to ship their behavioral data in real-time to Google. So, there is is still a place for a basic Linux-based family desktop that just runs a privacy-friendly browser.

That's not a desktop, it's a kiosk. Linux is actually fine for these kinds of single-tasking embedded use-cases.

But seriously, who does that? I don't know anyone who primarily uses a desktop computer just to browse the web. That's what tablets and phones are for. ChromeOS is just one of those with a bigger screen and a keyboard, which is why it is perfect for them.

"Family desktop" was only a thing in the brief period between the internet becoming popular with consumers and the first iPhone. Outside of that period, multi-user desktops (or microcomputers, if you recall the 80s) are an extreme edge case.

Don't forget about the educational market. ChromeOS is very popular in schools because of how locked down it is, and computer labs in schools are one of the few environments where multi-user desktops thrive.

Just in US schools though.

I hardly seen any Chromebook on sale, or being used in coffee shops, around European countries.

In Germany when they are on sale, they happen to be a single unit, discounted multiple times until it somehow disappears from the shop.