Women as 'breadwinners'

In the context of America's classic "mother, father, and 2.2 kids" household, we've grown accustomed to single-earner families where the breadwinner is a man and dual-income families where both a father and mother work. So why haven't we come to terms with single-earner families in which the woman is the breadwinner and the man a stay-at-home dad? M.P. Dunleavy wrote of the phenomenon in A Breadwinner Rethinks Gender Roles on Sunday:

The patterns that seem 'normal' when the husband is the breadwinner don’t hold up when women earn most or even all of the income.

Barbara Risman, a professor at University of Illinois-Chicago, says in the article that women don't receive the same "identity benefit" from being a breadwinner that men do—financial power hasn't given women the balance that they are looking for. I think that the idea of identity has a real relevance here, especially with Dunleavy's reference to "renegotiat[ing] expectations"—but I'm not sure where to go with it. Any thoughts?