I think women are still exploring all the implications of having equal rights to men, and all the social constructs throughout society are slowly being rewritten as a result.
True, women are physically weaker than men and yes they think in a different manner than men. I fail to see how physical strength matters in occupations where thinking is required more than physical labor. Also, as time goes by, with the assistance of more technology, we may find that many more occupations will be less reliant on physical strength. Women tend to be more intuitive than men on many things... and yes being more emotional (or drama queens) may not be helpful, but with discipline this can be tempered and made manageable. The intuitive quality in women is very useful in business... and the caring instinct has proven to be a useful quality for business women too... surprisingly.
This goes back to the old argument of which is better, men or women... Which really doesn't matter in the overall picture. Men and women are equal when you compare the sum of all their qualities. True, some men are better in certain things in life than women... and vice versa. Also, given resilience, I have found that both men and women can overcome shortcomings when they pursue things that their genders are not naturally best inclined for (i.e. men being caretakers... and women being cold, calculating business executives).
I think that marriage is being redefined as women assert new roles and find new ways to juggle these roles with having families... It makes sense that the idea of marriage would change as the women today are not in the same roles (or limited to them anyway) or even mindsets as those before the women rights movement.
"The weakest soul, knowing its own weakness, and believing this truth that strength can only be developed by effort and practice, will, thus believing, at once begin to exert itself, and, adding effort to effort, patience to patience, and strength to strength, will never cease to develop, and will at last grow divinely strong."
- James Allen