This is my own opinion, and completely anecdotal, but having children can help improve your quality of life in several ways. Children can provide parents a sense of purpose. Parents are responsible for the well-being of their children, and this obligation in-turn forces parents to become less self-centered, and focus on something other than themselves. The relationships parents develop with their children is also unique to any other bond. They represent a piece of you, and are completely dependent on your for everything. That dependence, when coupled with the love they have for you, can give your life new meaning and joy.