[The Squatter of Amon Rûdh]

Actually ancient matriarchies and the displacement thereof by patriarchal Semitic tribes forms a strong component in Robert Graves' view of Greek mythology. He was a contemporary of Tolkien's and, what with JRRT not being unconnected with mythography himself, I should think that he was aware of the existence of such past societies.
Moreover, the Anglo-Saxon world that Tolkien studied in such detail was more egalitarian in its gender mores than a lot of people suppose; more so than that of their Norman usurpers at least: King Alfred's daughter, Æthelflæd, is consistently portrayed as being the real power in Mercia, some Irish sources feeling the need to justify her strong role through a phantom illness of her husband's.

My view tends towards that expressed by several people in this discussion, that Tolkien felt more comfortable writing about men, but we shouldn't point overly much at his cloistered life as he was a married man and father. I think that he was uncertain of himself when it came to writing about women, and that this was exacerbated by the style he chose. As for Arwen Evenstar, who sparked off all this debate, I should say that the lady who could give up her people not just for life, but for eternity in return for the uncertain fate of mankind; who could stand to wait for years while her man risked his life countless times, and to see the stress it placed on him and still be a support when he did turn up is a strong enough character for my taste, if a little unfashionable. People these days often underestimate the strength of character it takes NOT to go on the adventure, and to hold the fort instead, which is just as vital a part to play, if less glorious (note the role of Fredegar Bolger). Anyway, that's my rambling two-penn'orth