There are plenty of situations in which co-parenting is not the best choice. This article on HuffPost.com details 5 reasons why it might be the preferred arrangement for parents who are not able to get along.
I found this interesting article on Babygaga.com about "parallel parenting" as opposed to co-parenting. The jist of it is that parallel parenting is ideal in cases where the parents to a child engage in a more business like relationship when it comes to parenting. Co-parenting is only possible when the two parents involved can communicate and work together on a mutually agreed upon parenting plan. When communication and collaboration are not possible, parallel parenting is the next best thing. Read more about parallel parenting here.
Write something about yourself. No need to be fancy, just an overview.