This is buying into the idea of rugged individualism when it comes to parenting. That all a child needs is their parents and that time away from children is a failure of parents. This couldn't be further from the truth. Many studies show that children raised in a cooperative environment where they are exposed to various people and practices from extended family, professionals, teachers, etc help reinforce social connectedness.
Not to mention parents have more to them to simply being parents. Their own desires, wants, and needs. Balancing these with being parents leads to the more fulfillment.