He gets mad when parents use their children as pawns in their relationship. When they use them as leverage. When they attempt to create an image of the other parent that's just based on their own. When they say disparaging things about one another in front of the children. When parents fight in front of the children. When they bring their children into their arguments forcing the kids to choose sides.
Dr. Phil is a very insightful man who has such a huge heart when it comes to children. Being a parent is the most important role for the future of our country; we need to treat it as such.