What I am saying is that regardless, if a parents' marriage is ***but at least one of the parents isn't terrible, the child is better off in a single-parent household with the better parent, be it the mother or father.
Even then it would be subjective.
How can we, or even the courts, define what is better?
Situation 1: Two parents get a divorce. The father is a drunkard, who becomes very violent while intoxicated, but is also a CEO at a local, mid-level business making almost 7 figures a year. The mother is a meek, under-developed (due to a birth defect) woman who cannot work, but is loving and caring for the child/ren.
Situation 2: Two parents get a divorce. The father is an Iraq vet who collects disability due to his leg being blown off during the war, and doesn't have a job to support himself. He suffers from PTSD. The mother is a high-earning socialite who's main job is to create medicine that helps cure cancer.
In situation 1, the father can financially provide for the child, but the child may not have the best situation when it comes to attention and care. While the mother can take care of the child, she cannot be there for the child during social events (graduation, sports, band, etc.) and cannot provide for the family itself. Which is the court going to allow to stay with?
In situation 2, the father has the ability to care for the child, both financially and figuratively, but not emotionally. The mother can care for the child financially and emotionally, but not figuratively (no time to take care of the child if you are always in research mode). Which parent gets the kid?
The answer is never easy, and the answer is never correct, because not enough information is given about any of the parents in regards to how they handle certain situations (given that those situations generally haven't occurred yet). The courts could decide to give the child to the mother in situation 1, but in an alternate universe, where the child went to the father, they may had a more fulfilling life because of having to deal with a drunkard father.
We will never know, ever.