The Glory of the Coming of the LOTD

2007 for me was the year of Linux on the desktop. My sister's Frankenstein computer, cobbled together from half an old Compaq and half spare parts had finally accrued so much malware that it had to be reinstalled. The XP installation on it was already pirated so there was no installation media, leaving the following options:
1. Buy an XP license. This being pre ad-financed windows I think a license cost something like $150. This was more than the PC itself was worth and not something we were willing to spend on.
2. Install a pirated version. A dicey proposition and likely to bring just as much malware as we started with.
3. Install Linux.

The only reason number 3 was even an option was due to a relative newcomer to Linux distros called Ubuntu. There were other distros aimed at desktops like Fedora and SUSE but they never brought the same amount of polish that Ubuntu did. It's a difficult thing to quantify but just the combination of a nice installer, easy layout, configuration software and updates that didn't crash everything made it a minor revolution. It really just worked. So I figured we'd give option 3 a shot and for over a year she was able to use it with almost no problems. Most users only ever need a browser, media player and simple office suite. You even had flash player, a crucial component at the time.

There seemed to be considerable interest for using Linux on the desktop in general around this time, greatly aided by the failed launch of Windows Vista.
The city of Munich wanted to switch all their machines to Linux. Something that ran into the sand eventually just like the general momentum behind Linux on the desktop but why was that? Having tried a lot of distros around that time I think it had to do with all the major players being involved in massive overhauls all at the same time.

KDE

KDE was first out of the gate when it came to making major changes by introducing Plasma in 08, something that was not only widely panned on usability grounds but also began years of instability. I didn't get the hate for the UI, it seemed like a pretty normal Windows look-alike but I can attest to the instability of KDE. Only having used it briefly the one thing I do remember was this icon on the task bar you could click that would bring up a little speech bubble in which error messages were scrolling by at the speed of light. This was years after 08 and stability was still a bit sketchy so I can't imagine what it must have been like at the launch of Plasma.

Ubuntu

Ubuntu went with Unity a few years later. Chasing the white whale of unifying mobile and desktop UIs that a lot of companies including Microsoft would be attempting and just like all the other attempts it never quite worked. The whole idea is a folly and a stumbling block, you can't have a unified UI for different input methods. There were also some bizarre UI choices in early versions of Unity like the thumb in a scrollbar wasn't visible until you moved the mouse over it making you having to hunt for the thumb with the mouse every time you wanted to scroll. Most of these kinks have been ironed out but it's still not a very pleasant UI to use.
Another problem with Unity was that it was a resource hog compared to the old GTK 2 UI and ran sluggish on computers of the time.

Gnome

Gnome Shell came out around the same time and I knew it was gonna be bad just from trying to switch applications.
In most UI's this is done by moving the cursor to the running program in the taskbar and clicking on it. Total mouse movements amount to: 1 cursor movement, 1 click.
Gnome thought they could improve this UI mainstay by having you first move the cursor to the activities button in the upper left corner, click it, get a screen of running programs, move the cursor the the program you want to switch to and click on it.
Making for a total of 2 cursor movements and 2 clicks or an increase in the amount of moving and clicking by 100%. This might seem a petty grievance but you do this a lot when using a desktop UI so it inevitably starts to grind on you and the whole UI felt like this for me. Everything was just a little bit more cumbersome with changes that seemed to have been made just for the sake of not being like Windows.
If there's one thing Gnome has in abundance however it's excuses. People complaining about the application switching are usually told to use some key combo instead. But then why even have a needlessly complicated way of doing it with the mouse? It's often stated that it's really made for power users. A claim that is somewhat handicapped by the fact that Red Hat in Red Hat Enterprise Linux, their power user OS, run Gnome Classic by default which is Gnome emulating Windows 95 poorly. When Microsoft decided to create a new UI with Windows 8 they at least had the balls to make it default for all users.
The configuration options were very anemic compared to the previous Gnome versions, these are some of the thing I remember they didn't want you to change:
1. Volume stepping. When pressing the volume up key on my keyboard the volume would to from too quiet to too loud without any level that was just right. Easy thing to fix I though, I'll adjust the stepping. This used to be configurable but with gnome shell they made it hard-coded seemingly out of spite. It's locked to volume increments of 6% with a key combo, then after 6 years of people bitching Gnome finally came up with a solution which was to add another key combo that changed it in increments of 2%. Note that they did not remove the old key combo, they just added another one with a slightly smaller but still hard coded stepping... Good job guys that's some cracker jack software engineering right there. And this was done with no explanation or acknowledgement that they had been wrong.
2. Mouse scroll speed. Same as above, used to be configurable.
3. As soon as you closed the lid on your laptop it went to sleep and this could not be disabled. Any sane person can see that if you use an external monitor and keyboard this would be a problem. Again you found forum posts of confused users asking why this was removed from the config options with no explanation ever forthcoming. It was even remove from a Gnome Power Toys type program whose name I cannot remember. So someone apparently hated this feature enough to removed it twice from config utilities. It was still possible to disable this behavior but you needed to add a systemd one-liner to your startup script.
The whole thing felt very autistic like it's one guy's very specific desktop setup that he really likes and he cannot understand why the whole world wouldn't want to use.

My sister had to switch back to XP because of a secretarial correspondence course she signed up for that required activeX for their website. I don't think she'd be able to use Ubuntu or Gnome on her computer nowadays. Maybe Mint or SUSE. It's a moot point anyways now that they're practically giving away Windows.
I think Linux did have a chance to take a significant desktop share right around 2010 but all the major distros losing their collective minds lead to Linux not having any viable UIs for several crucial years right when the much improved Windows 7 showed up, putting a stop to any chance Linux had to make headway on the desktop.
Canonical also chose to focus on mobile which was a mistake since Ubuntu was pretty much the lone reason Linux was starting to be taken seriously on the desktop.
People underestimate what an apotheosis of UI design Windows 95 really was. It had actual science and usability studies behind it going all the way back to Xerox PARC where it stole it's ideas from. It's a very insular mentality that a bunch of programmers without any design sensibilities think they can make a better UI with no input from their end users, or in Gnomes case being outright hostile towards them.