Because people with children have more to care more about than themselves. They are more grateful for the job they have, and less willing to just walk away from

Because people with children have more to care more about than themselves. They are more grateful for the job they have, and less willing to just walk away from it, because they have other people's lives depending upon them. People with children make for more stable employees, and that is something employers value. And add to that, an employer is more likely to see parents as contributing to the society by rearing children. If you honestly do not see the value to society of rearing children, then I doubt I could convince you otherwise. Hint: It's the people willing to work hard at a job to provide for their family that you want procreating.