Time spent raising children should be shared in a way that the parents mutually agree on. Society has no legitimate interest in which gender does the work, as long as it's a mutually agreed to arrangement that both parties are equally happy with (or, probably more accurately, equally least-unsatisfied with).
> Society has no legitimate interest in which gender does the work
That's not really true. If all women chose to raise children instead of working, many products would have poorer design due to lack of diversity in ideas. And if 95% of women chose not to work, the 5% who want to work will have a harder time in many respects.
> And if 95% of women chose not to work, the 5% who want to work will have a harder time in many respects.
Why should the preferences of the 5% override the preferences of the 95%? A widespread norm of two incomes per household makes it much harder for women to be homemakers and full time mothers (since single income households have to compete with dual income households for positional goods like housing).
