Most people when considering divorce as the best answer to an unsatisfactory marriage think that it will bring an end to everything and a chance for a brand new start. It doesn't often do that.
Divorce is a process that radically alters the relationship but rarely severs it completely. This is always true when young children are involved. The idea that all will be sweetness and light as soon as the Decree Absolute drops through the letterbox is just not true.
Things do change
OK so you no longer have to feel the brunt of his anger and criticism or her constant nagging about how you don't pull your weight around the house. Neither of you need to fake being in the mood for sex when we're not and there are no arguments over whose turn it is to baths the kids or whether they can have ice cream if they didn't clear their plate.
The simple certainties are replaced by a fairer form of complexity
Maybe a total break was what divorce was like back in the days when mothers were almost always awarded full custody (now there's a word we don't hear any more) and dads could "visit" their kids. But those days are, fortunately, now all but disappeared.
The assumption was that once the family assets and the children had been allocated to one household or the other, each parent was free to pursue a new life unfettered by their previous relationship. How incredible that seems today. Then the children were treated in much the same way as the family car or the lawnmower (although you didn't get lawnmower visiting rights!).
The relationship never really goes away
Most divorcees learn relatively quickly that although we're no longer married and living together, we still have to deal with our former spouse in their continuing role as our kids' mum or dad. He or she needs to have a say and so a spirit of forgiveness and cooperation is the only way to proceed. Otherwise the battles of the marriage may well spill over into your life after divorce. Divorce no longer has to be seen as the end of a relationship but rather as a restructuring into a radically different but continuing relationship.
The divorce is just for you, don't share it!
"Just because you wanted to get rid of my dad/mum doesn't mean that I did too." Divorcing couples should see beyond their own situation and understand that the collapse of their relationship must not be allowed to destroy their childrens' relationships with either of their parents.
Divorce damages children, it always does
It cannot be avoided but it must be a priority in the divorce process to minimise this damage. The effect on children will always be long term. Who would want their middle aged child confiding in their counseller about the trauma they experienced when their dad left/was thrown out of their life? Nobody would want that and it really doesn't need to happen.