Not all programs require systemd to run, in particular, within containers. One
of them for example is boinc-client. Consider:

mkdir /c/etc
cp /etc/{passwd,group,shadow} /c/etc/
zypper -R /c in boinc-client
systemd-nspawn -D /c -u jengelh /bin/sh -c 'cd ~; exec /usr/bin/boinc-client'

This pulled in systemd not too long ago, but boinc does not actually use
systemd itself in any way. Therefore, boinc-client.rpm is not to have
requirements on systemd in its specfile, and in fact already had this removed
earlier in 2015 already.

A number of packages remain in openSUSE which still have these requirements on
systemd though they should not. These need to be audited and, as time and joy
permits, be edited to live without systemd where possible.

Points to note:
1. 17:48 < DimStar> I think the main issue of dropping the systemd_requires all
over the place is the fact that on a fresh system install, an rpm that might be
triggered for install CAN be installed before systemd - then having some fun
bugs to fix
17:51 < va> somehow we also manage to install aaa_base first, so if systemd
really had this "needs to be there" thing, it should not be a big deal.