Hi and welcome, Darthnibbles!
Were there aspects of the film that worked for you? I appreciated the cancer metaphor and that the whole team was made up of women. Not very often I get to see that. Usually the female perspective is relegated to a side character. I also really liked Jennifer Jason Leigh's ticks and fatalism and the film's exploration of self destruction...
OK, the cancer thing never really clicked for me although, on further reflection, the focus on self-destruction is a much better fit. In fact, cancer is merely one aspect or manifestation of that.
As for the female squad... It didn't matter to me. This is probably my male privilege showing, but it didn't seem like a big deal or anything unusual at all. Maybe that isn't my male privilege... Is male privilege when you're threatened by women? Then it's the opposite.
On the other hand... It didn't resonate with me as being really profound or out of the ordinary (neither did the recent Ghostbusters, though I loved the film) that it was helmed primarily by women, so perhaps I meant that it's my privilege which blinds me to the significance of it?
But! What was up with them going to the tower for protection, but the lookout is on the ground with a light on? And then when there is trouble, the rest leave the protection? That stupidity in plot pulls me right out of a movie. There are other aspects I'm not thrilled with, so I too am mixed.
This was just one of the silly decisions that were made "because the plot needed it," rather than being what intelligent characters would do. There were several like that that just galled me.
All in all, my opinion of the movie is improving as I think about it (I love it when that happens), focusing primarily on the Shimmer (and the characters' journey) as being an exploration of self destruction. Which is, given the ending of the film, quite fitting.