They fail to consider or address the underlying causes as to why women aren't becoming MPs. In other words, AWS tackle the symptoms, not the cause. This has been proven by the inclusion of mtf transitioners onto the shortlists. Many of the reasons why women might find it difficult to become an MP (esp anything to do with childcare) would almost not apply to an mtf transitioner. The fact that Labour don't seem to understand why AWS exist is concerning.
One possibility is that part of the reason for women not becoming involved is that they mistakenly think the work will not be compatible with parts of their lives like mothering. That might go some way to explaining why they were successful at increasing numbers, since as you say they don't change the basic situation.
If so, it might be possible to achieve more participation in other ways, for example I've seen places where they ran seminars for women who might be interested in getting involved, which mainly talked about the practical issues of political involvement.
On the other hand, I sometimes wonder if AWS might not mean people go out of their way to find women who will agree to stand, even if the women are sometimes not the highest caliber, because there are still many who have the various barriers that tend to affect women in place.