It's like how /r/steak is just dudes posting steak pictures, and there is some new cooking sub where it's just women posting food pictures and complaining about their significant others. Women be complaining.
I'm not sure how serious you are about the dismissive "women be complaining" comment. A big part of your perception may be that women have more to 'complain' about; society is measurably unfair for women. Another part could be that when women voice their struggles it is called "complaining," and when men voice their struggles they are "being serious." Also, men get shot down for showing vulnerability and seeking support, so their struggles are internal. And this isn't always good for mental health.
> there is some new cooking sub where it's just women posting food pictures and complaining about their significant others
If you are referring to /r/girldinnerdiaries, that is not a cooking sub, nor is it intended to be. The whole point is pairing a photo of dinner with the situation and mood of the photographer.
It's right there in the name: Girl Dinner Diaries.