Systemd does violate the one thing well principle set by the Unix founders.
It also violates the no1 security rule of running as little as possible as root.
Busybox does not violate this rule because you can select every utility you want. The reason it is one binary is purely due to embedded hardware limits such as fragmented memory. Note that systemd is not ideal at all for deeply embedded systems that these set top box designers work on, though the kernel like busybox is perfectly configurable and usable on these systems to a smaller size than systemds pid1 even, and don't tell me Lennart said it's better for embedded because it isn't, check out the embedded lists like buildroot or uclinux, android uses a tiny init and android size devices actually account for a little of the embedded market.
I actually prefer OpenBSD as a desktop system to Linux however I do use Linux purely due to the dev power to provide faster and easier package and system updates for a few systems as well as the security KMS video can offer and on one system to run software that will only run on Windows/Linux.
The OpenBSD init system is great and is easily and completely followed and edited, locked down and understood from init.c and /etc/rc to rc.shutdown. Openrc and sysvinit is harder but do-able. I would be there all year with systemd.
The main problem with linux init is the human interfacing. Systemd is an improvement over upstart but I'd rather run upstart even and OpenBSDs and openrc's interface is far more intuitve and better than systemds.
The problem of sshd dying before a shutdown can be completed does not require systemd to solve and is something I have only witnessed on Linux a while ago. How about systemd hanging rather than one shell hanging on boot before sshd has started, a far more common occurence from the mailing lists.
Systemd actually offers a very poor function gain to risk ratio when you pick through the many pre-existing/stolen features and many either wrong assumptions or purposeful lies.
The majority of Linux systems (Gentoo, Debian, Ubuntu) will never run systemd so have fun marginalising Gnome and launching mate and XFCE.
Oh and moving critical statically compiled binaries into a larger /usr as encouraged by Lennart and the FSF is a function/stability mistake too. Think about it, don't take historical hype and busybox hype as given.