All throughout history, there were the traditional home-affiliated women; it's not that women didn't work outside the home, but being home, married, with children, and managing one's own household was - generally speaking - the normal, optimal, desirable occupation, despite the first wave of feminism at the beginning of the 20-th century - right up until the 50's. Then came the big tide of 60's and 70's feminism, during which women flocked out of their homes and into the workforce en masse.
And what is going on now? Women are expected to be achievers in all areas of their life, to work and to have great marriages and have children and raise them perfectly through the urban myth of "quality time"... and although staying home is still counter-cultural in most areas, and being "just" a wife and Mom is underrated, more and more women are making this choice, realizing that no one can be or do everything, and that when you invest the larger portion of your time and energy someplace, something else inevitably suffers.
So what happened?
Basically, the women who are in their marriageable, childbearing, family-focused years today are very likely the children of feminists, of career-driven women, or at least of women who were forced by circumstances and newfound social norms to work long hours. Unlike the first generation of feminists, we know what it's like to have mothers who are seldom around, and we know the price the children pay for it. Therefore, women of our generation are more likely to think twice before deciding to make the same choice for their children.
Very often our mothers aren't getting us. They, after all, invested all those years in establishing themselves as professionals, and yet they were still our mothers, and perhaps were doing their best, or at least the best that could be had at the time, with what they had. When your children make radically different choices, it may sting as an accusation, as an "you weren't a good enough mother, so I'm doing my best to alienate myself from your ways. I will do all it takes to be your exact opposite."
It is, of course, also interesting to look at this from a different angle: how come a generation of homemakers (again, I am generalizing and simplifying, of course) produced a generation of feminists - moreover, feminists that disdained their mothers' role in society and made such a thorough job of forgetting what homemaking is all about that many of the home arts have all but disappeared?
I don't think there is a simple answer to this question, but here's something that has been on my mind: children will only want to follow in their parents' footsteps if their parents are happy, or at least generally satisfied with the way their life has played out. I do think there must have been a rising level of dissatisfaction in the last all-homemaker generation, dissatisfaction that the feminist movement played on to promote its goals.
It's easy to imagine that the typical, 50's urban homemaker might have been looked down upon, as someone boring and unimportant. The diminishing of the agricultural society caused a communal fractionating, the nuclear family no longer worked together as one unit. With the husband gone to his separate outside job throughout the day, and the children off at school - in addition, families were already typically smaller than a few decades prior to that - on a superficial level, it really might have looked like the housewife had nothing to do but dust shelves and bake cookies all day long, which just didn't seem as terribly important and indispensable. Were some women bored, unhappy? Probably yes. More importantly, their daughters saw a lifestyle they did not particularly desire to follow.
Was feminism the right answer? No, of course not. Feminism caused tremendous damage to everyone involved; feminism lead to additional fracturing of society, as homes became empty and everyone was pulled in different directions all day long. It took decades, but finally the truth dawned upon a whole generation of children whose mothers were overworked, frazzled and on a deeper level, more dissatisfied than the so-called "desperate housewife". The government, the "women's rights" movements and social studies teachers might be still playing the same old song, but we have become disillusioned.
PS: I have not studied sociology or the history of feminism on any level close to professional. What I offer is simply my own insights and observations, gathered from personal experience and perceptions of other women my age.