Earlier quoted context omitted.
They get the perk of more flexibility because they're providing a service to society, raising children for the next generation. You don't get this perk because you didn't have children. Your contribution is more work because you have more time to do it.
This argument is made again and again in this thread, and it never got addressed. 1. There are already functional mechanisms for contribution. A single, childless person is already contributing more through their taxes. The government already heavily subsidises child-rearing. 2. Child-rearing is given an arbitrary pass that other equally charitable actions wouldn't get. A single, childless person couldn't let his com…
2. Child-rearing is a thing tens of millions of people actually do interleaved with full-time work, and has to be addressed by high-level decision makers. There are lots of hypothetical things a specific individual might want to do that maybe have high social utility, and that's an interesting question for them to sort out with their manager and isn't really relevant to how parents are treated.
3. A stable population -- not growing -- requires a little over 2 children per woman, and the US fertility rate is waaaay below that right now.