When custody decisions are made by those who are focused more on financial issues than family issues, children's needs often get pushed aside in favor of other objectives. Relationships, balance and good will are not prime objectives in the battle of divorce, and the scars on your children's psyches are often overlooked in the legal blood-bath that ensues.
At some point after the wedding festivities died down, you woke up and realized that you'd made a mistake. After the infatuation faded you recognized that you didn't want to live with this person for the rest of your life. As you've both grown older you've both changed, but in different directions. Maybe it's the day after or maybe it's years down the road after you've had 2 or 3 children.
Some of the greatest moms and dads I know are also some of the worst parents I've ever seen. The worst offenders of that greatest bunch are the divorced moms and dads, because while they're trying so hard to be the better-liked parent, what's really "in the best interests of the kids," actually isn't.