Repeatedly saying, "add more females!" probably isn't going to result in them adding more females. Sakurai clearly doesn't buy in to quotas such as that. What that crowd needs to do is choose one character and rally behind her, because largely popular characters have a history of making it in.
It's actually one instance that the generalizing is a positive, as just pushing some token addition should, theoretically, spare people from internal character wars. It's not that that crowd wants "that female" so much as just, "a female". And sure it's a reductive strategy, but it fits a reductive demand. So pick one and get on it, because shouting into the ether for women, while well intentioned, in all likelihood won't amount to a whole lot.
Assuming, of course, it's not too late to affect future DLC anyway.