The fact that some women complain, is not a big evidence per se. Some men complain, too. The evidence is that the complaining seems coherent, is persistent, and there are no women saying: "actually, I think it is completely the other way."

Also, I would agree that it is important to maximize the number of rationalists, regardless of their demographics. But I would not be surprised if a small change of rules could make this site more attractive for many women, and still attractive enough for 95% of the men which are currently here. On the other hand I also would not be surprised if we will never have enough rational women here (or anywhere else), regardless of what we will do. Sorry, my model simply does not contain the information about what kind of a website can be best for rational women (with emphasis on both of these words). To be fair, before LW I also did not know what kind of a website would be best for rational men; I could not imagine rationality surviving in a group of more than five people. More data need to be gathered by an experiment.