systemd

I've been living with perfectly functioning Linux installations without all that udev-systemd-messagebus-whattheyarecalledtoday -- crap comfortably.
My /dev is fully populated and I don't care about a few inodes and MB of filesystem used by that (good filesystem don't have an inode limit anyway). My machines do always boot even if random stuff is missing or corrupt (and they won't with udev etc.). I've converted all CentOS/RH machines back to the good old style /dev system and it's been a relief: no more initrd, just boot the damn kernel via whatever you like. The startup is faster, too. All in all the system is simply robust.

Separating system directories (like /usr and /var) is what has made Unix great. It even helps performance (because of lesser locking) and fragmentation (yes, this is a problem on a write-intensive FS), let alone robustness (one FS can corrupt easily, but not 3 at the same time).
Being told by a freaking little program and their developers (who don't "believe" in separation) that I cannot do that is just ridiculous.
They've had their head too long in that "always on" mentality; they've not grasped proper System V init; they've forgotten about system init (not yet all mounts and maybe R/O) vs. system running (all's there) phases, which is a base paradigma of all technical systems.

I express my shock that those people are allowed to change the future of how we will be running our Linuxes; they maybe should get back to working on Ubuntu, where the "en vogue" seems to trump robust working concepts, and leave the rest of the world alone, just alongside with the Gnome people for removing important window manager buttons from their console.
We don't like to play with our systems, we like to run them in whatever hell breaks loose upon us.