1/ Maintaining init scripts is a significant part of the work to be done in a distribution, and systemd makes this task easier. 2/ Gnome started requiring syst

1/ Maintaining init scripts is a significant part of the work to be done in a distribution, and systemd makes this task easier. 2/ Gnome started requiring systemd (via the dependency of GDM on logind). So, if they want to keep supporting Gnome, they have a choice between switching to systemd or developping some shims. And it's probably safe to assume other major pieces of software (KDE?) will adopt similar requirements.