To change their behavior, to get them to persist more with their submissions, you'd have to change our entire culture. I've read studies that look at this issue of why women don't persist in the face of rejection, and while I can't summarize them in any detail right now, one conclusion that stuck in my head is that for women, not persisting in the face of rejection is a survival strategy. If you're living in a world in which your rights, your freedom, your health and survival are all contingent on the approval of the men in your life, then you get conditioned from a very young age to do what it takes to keep those men happy, to be pleasing. A woman who speaks up in a class and then gets ignored or verbally slapped down doesn't typically think, "Oh, I should come up with something better to say next time, to get a more positive response." Instead, she wonders what she did wrong, whether she shouldn't have spoken up at all, whether the teacher is angry with her now, whether it's too late to save her grade, whether she should drop the course, cut her losses, try to find another way to survive college...
I think this all becomes deeply unconscious very young, and often doesn't make sense in any given specific situation, as when you're submitting a magazine. But it applies sufficiently overall in society -- the general case is true, even if the specific isn't -- that women get the message strongly reinforced, on a daily basis, in a thousand tiny ways.
And look, I'd say that I'm an assertive, strong-minded, confident woman. But I fall into the same damn pattern, unless I really consciously fight against it. I have panic attacks at the thought of doing a contract negotiation at work, and need my (male) partner to talk me through it beforehand, and even when I get up the nerve, I have icy hands through the whole thing, and on some level, am convinced that they're going to just fire me for even daring to ask. When I submit to magazines, I almost never resubmit past the second or third attempt -- sometimes not past the first. There are a lot of magazines, after all, and it's easier to just try somewhere else...even if that means going down a tier or two. Women are trained to assess the risk in a situation, to cut our losses -- sometimes that's deeply counter-productive in the specific. But it's almost impossible to counter a lifetime of cultural training, even for me, even though I KNOW I should re-submit, over and over again, to the best markets. It doesn't even just feel like a waste of time -- it feels, on some weird subconscious level, dangerous. As if the editor will get angry at me for wasting his time.
And as I said, I do consciously try to overcome that. But if someone actually solicits me for a story or a poem -- that takes all that tension out of the equation. I'm delighted to try to write something for them, if I have time. I'm disappointed if they choose not to publish it after that, but I'm not going to hold a grudge -- I do, of course, understand that a solicitation is no guarantee of acceptance. Almost all of my short fiction and poetry publications in the last decade have come from solicited submissions. Is that ideal for my career? Obviously not. But those are also the facts on the ground, and I, and editors who care about publishing women, need to take that into account.