It's probably partly sexism, but I think it's also because the story shape can become so different than a narrative that fits the male-dominated mode that viewers find it straight-up hard to process.

I agree with that. I saw it really obviously in action with Carol (2015), which was frequently praised for its sumptuous style by the same mainstream reviews that found it emotionally cold or at least opaque. It's not cold at all. Its protagonists aren't hard to get close to. I saw it with two other queer AFAB people and we all thought the scenes between Blanchett and Mara were electric. It's just that if you can't read chemistry between women, especially women in a closeted era in which all moves of investigation let alone courtship must be made through very careful codes until relatively (to a straight, as often as not male viewer) late in the game, then apparently their relationship feels detached, arbitrary, difficult to get hold of, and you say as much in print and look to queer and/or female viewers like a critic who just didn't see the actual movie.

There must already be a book of feminist film criticism called The Movies Men Don't See.