I have a hunch that the nominally feminine gender is rather one of subjunction, not to say subjugation. Der Himmel -> Die Sonne -> Das Wetter. Der Tag -> Die Nacht -> Das Jahr. Der Mond -> Die Sterne -> Das Pantheon ... OK, I am not quite sure, but at least gender was an innovation in Germanic, whereas the reconstructed Proto-Indo-European knew inflection for in-/animate -- e.g. there were two different words for fire, where the the other gave ignition [1].

It stands to reason that the feminin came to be at the boundary between these.

[1] https://en.wiktionary.org/wiki/Reconstruction:Proto-Indo-Eur...

PS: This is fun ... Der Mensch -> Die Familie -> Das Dorf. Der Krieger, die Krieger, das Kriegen. Der Aktionär -> die Aktie. Die Aktionärinnen ... das Aktienpaket. Der Karren (car), Die Karre (load), das Ankarren, das Herangekarrte, das Karree (See [2] for more on four wheels, strange animism, etc. Ultimately inconclusive).

Note that the pluralizing morpheme -en was written -in in old german. Also note that many case inflections come out as -en, so I suppose that female forms were in the objectified part of speech more often, where the gender is not reflected in the article (den Kindern, Männern, Frauen).

[2] http://langevo.blogspot.de/2014/09/four-map.html