Excellent observations. Of course there are great female authors, so it's not exactly fair to paint the entire gender with one brush. But I think women's pragmatism stems from the fact that females, as a sex, evolved as specialists, designed for a specific function, which not only makes them vulnerable, but makes them lean toward perspectives that redound to their safety and security. Men, on the other hand, have got to take risks, because if they don't (and this is a gross oversimplification) there might not be food on the table for tomorrow, or the tribe next door might wipe you out.
Heloise is another brilliant historical female mind (of Abelard and Heloise). Her writing is extraordinary.
Austin's unique perspective in her many works also reflect your sentiments.
Bronte and Shelley break the mold, with fabulous results.
Historical factors may have also played on part in the prominence of masculine great works. Women were typically the connecting point between the family and the rest of society; as a result, their attentions were devoted to not just home and family, but to maintaining the bonds between their families and other families. This served to occupy the vast majority of their time, leaving room for little else. Great historical female writers may have gone unnotice or failed to flourish for sheer lack of time.
Improbable? Not really. My own experience is such that after the birth of my first child, my writing took a back seat to the needs of my son. After my daughter came, I found myself in near retirement status. Only now, several years later, am I finding a few moments here and there to write. Given the tools available to our ancestors, it is actually easier for me to put together 30 pages of material than it was for them...by virtue of the fact that I can type 100 words per minute, versus writing them with quill and ink, or pen and pencil by hand.