I decided to search for some of those positive reviews, as it does seem like it might be an interesting read potentially. This one seems to be one such, though then again I also came across this which is much closer to your take. The former did raise a question which I'd also been wondering, which is how this book compares to Le Guin's classic "Left Hand of Darkness", but I'm guessing the answer to that is as subjective as one's opinion of the book in general, and likely closely aligned with it.
Such a thing as that usage of "she" does seem like one of those things that can be powerful for one reader and add a lot to the whole book, while being instantly dismissed as a "gimmick" by another, dragging the whole book down with it. I'm reminded of my viscerally negative reaction to Atwood's "The Handmaid's Tale" - the woman most definitely can write (The Blind Assassin is excellent), but she ticked a few wrong boxes and it ruined the whole novel for me, so that I have a hard time understanding the praise it gets from many readers.
Though it seems from your review that your lukewarm reaction had many more factors to it than just that one - still, if it had somehow "clicked" for you, you might've been much more willing to overlook the other flaws you note?