Ensure Civil Relations. Even though a court can set custody and visitation arrangements, it will not be present every Friday when it is time for mom to drop off the kids, and it will not spend the weekend with dad, making sure he does not make snide comments about mom around the children. Ultimately, a court order is just a piece of paper.  Mom and dad will STILL have to civilly deal with each other to carry out the terms of the custody and visitation order. Divorce does not take away your responsibility towards your children, and this includes dealing with their other parent, because divorce does not make your ex-spouse any less your child's parent (one exception being cases of abuse).

Maintain Your Standard of Living. You should also recognize that a divorce court cannot increase your salary to prevent your standard of living from declining once you divorce.  Unfortunately, from an economic standpoint, it is simply much cheaper for two people to live together and share expenses than it is to maintain two separate households.  Divorce will change your standard of living and there is little, if anything, the court can do about the change. 

Resolve Emotional Issues. Finally, a court will not be able to punish your ex-spouse or morally vindicate you for all of the bad things that happened while you were married.  Moreover, the divorce process will not heal your emotional wounds or even take away the necessity of grieving the failed relationship.  That is your job, although you can seek assistance through therapists and support groups.