You're changing the goalposts. The initial discussion was about gnome, and their desires to ignore the many many other kernels it currently runs on in a short sighted desire to minimize developer issues. In those cases, it is absolutely a detriment to the community to force more and more requirements on systemd, instead of putting out specifications for generic dbus consumers and producers. In this context, I would definitely argue that it's not in the project's best interests to depend on another project that has stated they have no intention to make things work across different kernels.
This is the issue that people who only deal with linux don't understand. Were I to try to put software in gnome that depended on features only found in ZFS, I would be rightfully criticized for it. Why should Linux-only features get a free pass?
What you're saying is utterly incorrect, speaking as a GNOME release team member. Pretty poor to first complain about moving goalposts, yet at the same time misrepresent what was done.
In the beginning of 2012 (Jan/Feb) I highlighted the various problems. Nobody stood up to help out. Now it is 2014 and we do NOT rely on systemd.
Further, we DO rely on dbus APIs and can rely on ConsoleKit still.
What was done was certain parties made a one-sided announcement that ConsoleKit was deprecated without any discussion regarding the people who used it. Where was the call for new maintainers? Where was the call to see if the project still was viable? Re-reading the "discussion" thread still feels to all the world like a decision was made, regardless of the merits of keeping the project alive, because Lennart et al wanted to move everyone kicking and screaming to their new toy.
Furthermore, where is the GDM documentation on what it produces/consumes regarding dbus? Where's the API spec. I can find that it does use org.gnome.DisplayManager as its root, but what more from there? I have the feeling that few people are willing to help out here because Gnome feels about as transparent as a brick regarding these decisions.
This is the issue that people who only deal with linux don't understand. Were I to try to put software in gnome that depended on features only found in ZFS, I would be rightfully criticized for it. Why should Linux-only features get a free pass?