When you run an init system like systemd that requires a helper program to start services (systemctl), it is not easily possible to start services in a chroot, because the chrooted systemctl cannot connect to the outer systemd.
Using init scripts or a different type of cli that does not require another daemon to run (like sysvinit does with the shell scripts below /etc/{rc.d,init.d}), solves this problem.
There is a detailled description of the problem at 0pointer.de.
So in short, running services in a chrooted environment became harder with systemd.