Why can't we all just get along --post divorce that is!

Divorce is tough enough, but post-divorce is even tougher!  When you are married there are certain parenting issues that you are willing to overcome.  However, after the divorce, parents often will not let those thing slide.  The tough part is keeping their displeasure from the children.  I wonder what would happen if a Court could impose a small monetary fine each time a person speaks ill of the former spouse (except in court proceedings)?  It would make post-divorce more like being a professional athlete who can be fined for verbal indiscretions.  Would this derail the bad-mouthing parent?