I continually trip over the Super key which brings up the Unity version of Spotlight. I killed Spotlight on my Mac a long time ago. I killed whatever Unity thingy the Alt key used to do. Was it the Alt key it hijacked? I don't remember. I don't even remember what weird UI it was trying to foist on me. It was annoying.
I killed the Guest user, but it reappeared with subsequent updates. I still sometimes get logged in as the Guest user, just annoying. And why does the login screen forget the state of the NumLock key? When we type in numbers that might be in our password, we get cursor keyed to the next or previous user in the list. Fun times.
I stopped using LibreOffice. I so much wish I could kill the office ecosystem, it is dreadful. Stop sending me .doc files. My solution is to use an ancient version of Word on an old Mac, and it prompts me so that I can avoid running those Word Macros.
My production server runs Linux (for years now), and I am surprised by how robust it is. A desktop is much more complicated to do well, to satisfy everyone's whims, never mind all of my strange choices.
Not even particularly a desktop issue, but: init cron rc rc.local upstart systemd runit launchd daemontools srvscanner inetd xinetd StartupItems grub2 SystemStarter (I am sure there are many more.) Do I care? No. Ah yes Linux, all of those choices, doesn't even have to be Linux, flavor of the week of BSD anyone? And if I don't like them ... it's open source, so I can "simply" fork my own turd. Not. </rant>