Funnily enough, I agree with both of you. Cyberax's points are entirely valid. As someone who likes to use cgroups and their various incarnations to manually carve up systems for maximum performance and utilization, the echo / mkdir / rmdir based interface is a breeze. Rolling this all into systemd is not going to negate, but make what I currently do quite easily very very difficult.
Myself and many others in the HPC industry are likely not pleased with this decision whatsoever. That being said, I do love systemd overall, just not this specific part of it.