Organisations devoid of talented women are running out of excuses considering the high numbers of female university graduates, says Wittenberg-Cox, who is recognised by ELLE magazine as one of the top 40 global women leading change.
"The big shift is, educated talent has gone majority-female everywhere. For companies who say: 'We recruit and promote on competence,' that argument is wearing thin if they are promoting 80, 90 per cent men yet we have been above 50 per cent women graduates for a long time."
Most organisations hand the task of defining the business case on gender equality to the HR department, the head of diversity or a senior women's network. But this can be limiting, says the author, because HR departments tend to look at gender in the context of talent issues and are unlikely to widen their vision to include market strategies, product sales and customer relationships.
"A complete business case on gender is transversal and needs to take into account other parts of the organisation, principally product development, market research, marketing, sales and customer service."
Meanwhile, empowered working women of the 21st century are expecting their organisations to adapt to them, not to have to adapt to men's ways of working, warns the author. They will achieve this through sheer force of numbers. "The massive arrival of women in the workforce - we have not experienced this kind of social change on a global scale before. I think a lot of people underestimate how big a revolution this is and the consequences of that.
"There's a fork in the road. Some companies are adapting, other companies expect women to adapt to them. I think all companies who want to survive want to become much more gender-bilingual."
Another strong message from Wittenberg-Cox is the challenge for working mothers, who peak in their careers a decade later than men after having children in their 30s.
"Most companies develop talent between 30 and 35 - if companies have one policy that eliminates women from the pipeline, that's it."
Wittenberg-Cox points out that in many organisations, if you are not ahead by 40, you are "mommy tracked" (put on a different career pathway with more family-friendly working hours) and will never be considered for the big jobs.
"In most organisations, the career train passes only once and if you miss it, you can't get back on - ever."
Companies must recognise and adapt their career management cycles to women's different career patterns, says Wittenberg-Cox. Otherwise, women will keep falling into the hole; sidelined and squandered as "mothers".
Language is extremely important in organisations, claims Wittenberg-Cox. "The "glass ceiling" is an unfortunate metaphor, implying women are moving up smoothly through the ranks and getting blocked at the top.
It's a lot more endemic that that, she says. "It is in the very walls and cultures of companies. I call it gender asbestos ... the number of women relative to men drops at almost every management layer."
Wittenberg-Cox is trying to shift the focus away from having women on boards to having a good percentage of women on executive teams.
"Australian corporate boards have improved, but executive teams have gone from 19 to 15 per cent, probably because they've gone up to the boards. With boards, it's a lot easier to 'parachute' women into non-executive roles rather than having them at every level."
At ANZ NZ, there are three women on the bank's executive team out of 10. At least one woman must be shortlisted for every role.
One of the executive team, Felicity Evans, general manager of HR, says that in the wake of Wittenberg-Cox's visit, the bank will make some changes. "It made us rethink the language. Rather than diversity, we now use gender balance."
The mother of two, whose husband is the family's primary caregiver, was struck by the concern that the bank might not be accommodating high-potential women who may not "peak" until their 40s because of having families in their 30s.
"Are we guilty of that? What are we doing to do to mitigate that? It [may be] one of these traps we have mistakenly fallen into," she says.
The bank would look at when it identifies talent, moving the process earlier or later to account for family responsibilities.