As a Gentoo user who likes to cut out bloat, I HATE systemd, and now udev. udev now has networkmanager, systemd, and udev all as part of the same project, now. This huge bloat now makes it so that you can't even boot without an initramdisk (something I don't use) if you mount /usr on a different partition (which I do, because my /usr lives on an ssd). Not to mention, networkmanager uses a binary format for config. It's especially bad for embedded systems. I really don't want anything remotely like a Registry in linux. udev just keeps growing. Things like hotplug were perfectly fine as separate services. There's no reason to make everything monolithic, and is very contrary to Unix design philosophy.
If anything, I'd like to see things moving the direction of plan9. For example: wayland. A great way to make it very unix-y would be to make a virtual filesystem to handle creating windows in the style of plan9's /net. Have a command/syscall mkopengl, which would create /dev/opengl/{context,control,input,monitor,fb,data/}. context and control would have things like the window location and size. Updating those would just mean writing to those files. OpenGL instructions would be written to input. Reading from monitor would stream OpenGL commands written to that context. Reading from fb would grab the fully rendered frames (just cat into a file/encode from to record). Finally, data could have file descriptors to textures in video memory. Not only would a setup like this be powerful in terms of being able to chain programs together, but network transparency would simply be a matter of union mounting the remote /dev/opengl on top of the local /dev/opengl (the way NAT, etc works on plan9), or cat-ing from monitor into a local input "file".