Contrary to popular belief, kids are not some tamagotchi pet that needs constant attention and helicoptering after they're babies. You can perfectly be a good parent and raise independent well minded kids without needing two parents always present every moment of every weekend.
And this is a good enough reason to expect people to work on the weekend? Kids are not some tamagotchi pet that exists as it is for a long time... kids are constantly growing and if you blink, you miss it. Some people would rather spend their weekends with their kids for purposes other than just keeping them alive.
No, but until they're mid-teens, they do need one parent most of the time. If one of them is working weekends a lot, then that assumes the other one is available to parent.
