Because it would be TOTALLY OUTRAGEOUS to expect a father to participate equally in the raising of his child.
I am sure that that is not what you are trying to say. Could you maybe explain why it is that man cannot have an equal (or larger) part in raising their children?
This means that never-married fathers have few if any rights that are not contingent first on responsibilities, while never-married mothers control the legal process every step of the way. In fact, the mother is not (and cannot be) legally required even to inform the father that he is a father and can hence give up the child for adoption without the father being able to assert custody.
There is no solution to this problem (of equality in parenting for never-married couples) that we as a society can live with, so it is then obvious that fathers cannot be legally or socially equal parents.
Now among married couples this comes into play too but differently. If a woman has an affair and gets pregnant by another man and the husband doesn't find out about it for, say, 3 years, the child is legally his and even if they divorce he may have to support someone else's child.
This means that for women, motherhood is both a biological and social fact, but for men fatherhood is purely a social/legal fact.
BTW, this also raises interesting issues--- it means that because as men and women can never be equal parents in our society, the ways in which we enforce this also mean that same-sex couples can not be fully equal to opposite-sex couples--- they either end up legally favored or disfavored depending on how presumption of paternity works in a given state.
It would be far better to ensure that taking a year or two off would allow smooth resumption of the tenure track. That's the fix.
Of course, then einhverfr went on to the whole abortion/child-support/false-paternity thing, so I don't know anymore.
The thing is, our economy is based on two fundamental assumptions:
1) Labor and capital are separate. Capital hires labor. 2) Labor works outside the home, capital can control things.
The second problem arises pretty clearly (and intractably) from the sort of worker protection laws that Belloc describes in "The Servile State." I.e., by treating employees as the responsibility of the employer, you have serious issues regarding workers comp and so forth when an employee is working outside of an environment that the employer controls.
The example Belloc gives is this:
A farmer hires two men to dig a well. The first is being lowered into the hole by the second and he lets the rope slip and the first worker is injured. If all three were independent agents, the first worker's lawsuit would be against the second worker, but instead it is the employer who is responsible. So this leads to an employer legally compelled to control the workplace. Things like telecommuting are challenging this but only seem to work in certain narrow domains.
So a lot of kinds of work cannot be done in the home for this sort of reason. This means that family life cannot be integrated with work life and therefore must be separate.
To me the answer is to recognize that a labor/capital divide in context with fundamental differences in the nature of motherhood and fatherhood, leads to economic discrimination against women. If we recognize that, then we can challenge that divide and build a more just economy based on smaller units where work life and family life are not so separate.
So these are all pieces of a very complex cultural phenomenon.
Has anyone advocated against this?