Haven't read TFA and I'm not going to because the answer seems obvious. I'd say this is mainly because a huge portion of (at least older) pilots were in the air force/navy and historically (unsure about now) women weren't flying in the air force/navy. The military is still pretty much a "men's world" and I think its probably the last place in society that we'll see an equal number of men and women on each task. Is it right? No, but that's what it is.