I suspect that the research side of traditional publishing isn't very well organised or funded, so it wouldn't surprise me if publishing turned out to be governed by perception rather than proper analysis.
Well this is it, isn't it? At LBF yesterday I listened to Jo Fletcher and Ian Drury both say that it's impossible to say what's going to be a hit, but you know it when you see it, and even then you can get it wrong. Research is pretty worthless, but the big publishers probably think they at least have to try. The gateway to the industry is not objective, it's subjective, and based upon certain people's opinions, which is what makes publishing, and the attempt to get one's work published, a frustrating and emotive topic of discussion. So I'm not surprised that research into what makes a hit is aimless and/or meaningless.
It could be that the subjectivity of publishing creates perceptions of inequity, and as Hex says, a innate sense of conservatism may lead to skewed publishing / reading / writing statistics among the sexes, which may be perceived, or may be very real. But there are lots of women in the SFF business who are successful and impressive: I'll name check Jo Fletcher again; Ella Diamond Khan, Bryony Woods and Elinor Cooper at DKW; Emma and Tik at Snowbooks; Carolyn Whitaker, and more that I can't recall off the top of my head, but there are many.
All of which lead me to think that the statistics are driven by the skewed number of submissions, where men seem to sub more than women. So what's the root cause of that? One possible answer is representation within the work itself. One old saw is, "if I don't see myself somewhere, then I feel I don't belong there." So the inclusion of a range of personas in literature (where appropriate, and it's not always) helps to dispel that idea of lack of representation, which in turn encourages participation, and over time, you may gradually arrive at equity. But it ain't a quick fix.
And lastly, as a writer with a massive stake in a product, why wouldn't I want to make it as attractive to as many different audiences as possible?