I don't see why your BeagleBone black example is systemd's fault. It has a convoluted way of managing network interfaces because it uses connman, a network-management daemon from Intel that is not part of systemd.
I installed ubuntu 14.04 on my BBBs. (Had to upgrade the kernel a little later because the 3.13.0 kernel wasn't ported to arm-on-bone in time to go out with the original 14.04 distribution and the 2.whatever they shipped didn't handle a class of USB device I needed, but it's fine now at 3.13.6-bone8.)
Changing to a specified, fixed, IP address was just a matter of editing /etc/network/interfaces, which was commented well enough (in combination with the man page on my ubuntu laptop) to make it easy.
(Main problem was that DeviceTree overlays weren't supported by 3.13.0-6, so I had to hack the boot-time base device tree to reconfigure for the onboard device functionality I wanted, rather than just overlaying the deltas during or just after the boot procerss.)