Comment # 6 on bug 948555 from Dr. Werner Fink

(In reply to Marcus Meissner from comment #4)

IMHO this is a bug of grub2!  We had in past serveral bugs that systemd is
ignoring the `ro' parameter and now as it reacts on the `ro' parameter a broken
grub2 configuration breaks exactly this fix!

Asking the original reporter that systemd should respect the `ro' parameter:
Now what is todo in this case?  Systemd does not know if the `ro' has been
specified on the kernels command line by the system adminstrator or is part of
the grub2 configuration.