I may be overgeneralizing a bit, but I think the reason divorces are up is because women aren't dependent for survival on their husbands the way they once were. They leave because they can.
Often these days you have a husband that expects roles to be the way they were in his house growing up, with the wife waiting hand and foot on the husband and kids, even though these days she's probably working as many hours outside the home as he is. He expects her to defer to his judgment at all times, even though she's probably at least as educated and well-read as he is.
On the other hand, you also have cases where the unreasonable nagging wife expects the husband to change at her whim, and gets frustrated and leaves when she realizes men don't work that way.
And then of course, you have young Christians who want to screw each other real bad, so they get married for the exclusive purpose of getting laid "legally" even though they have no business getting married.
In each of these cases, the woman is no longer trapped in the relationship.