Comment # 31 on bug 902612 from Thomas Blume

IMHO, we should make a distinction between essential system mounts and optional
ones.
Essential mounts that can't be umounted or umounting them would break the
system, should stay under the control of systemd.
For those mounts, manual manipulation in the running system is not desired
anyway, but automatic recovery at device re-appearance is.
If someone really want's to umount them manually, an extra step for disabling
the mount unit could be considered a safety measure.

For all optional mounts, it seems that systemd control raises more problems
than doing good.
Hence, I would opt to not control them via systemd.

If we keep everything in one fstab, maybe we could add an x-systemd- mount
option to distinguish between essential and optional mounts?
I guess such an option has good chances to get upstream acceptance.
Any objection?