I'm not sure where the thoughts on the de WP that GFDL-1.2 is not free came from specifically, but I suspect that they are thinking solely in terms of print reuse - not that significant. The most important downstream use of Commons materiel is electronic anyway, so GFDL-1.2 is as free as Wikipedia at the present.
As for my rationale, I tried to avoid weighing up the template itself heavily (apart from to see that there are good reasons on both sides). I've given a more detailed rationale to my decision at http://commons.wikimedia.org/w/index.php?title=Commons:Disputes_noticeboard&... and I think I'm right in saying that most contributors to this thread who had not participated on COM:DEL, only became aware of it due to my initial post.
I agree with Bryan's initial post here: misuse of a template should be dealt with by resolving issues with the users not the template. The help of de.wp admins to determine what images have been made less free through this would be beneficial, but that exploit is no reason to delete in of and as of itself imo.