"Basic OS building blocks" means that systemd aims to provide low-level tools that you can reliably depend on across distributions. In particular those pieces t

"Basic OS building blocks" means that systemd aims to provide low-level tools that you can reliably depend on across distributions. In particular those pieces that are currently implemented through distribution-specific init scripts of various quality and robustness. Network configuration in particular varies greatly from distribution to distribution, having a common, shared system would be a great improvement over the status quo.