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.
We don't see how they cope with the realities of life. We don't see how they adjust to living together or what happens after the wedding and the honeymoon. Most of all, we don't see how couples stay together, year after year, through raising kids, job losses, ill health, in laws and all the other daily things that make up a life.