Parenthood is like a corporation. Its sole assets are the children. The parents comprise the board of directors which govern the corporation. The duty of the board of directors is to preserve the assets of the corporation. If the assets are allowed to dissipate, the corporation will fold.
Parents should try to govern together like a board of directors to protect and preserve their children. Directors do not have to love each other, live together or even like each other, but they must govern cooperatively and effectively.
If you can think of the goal and mission of your parenthood as preserving its assets, your children, then perhaps you can relate to your spouse or ex-spouse in a less emotional way.