Childcare is mind numbing work, especially with young kids. Sure, some women (and men) would prefer that, but a LOT of women prefer office work over raising children.
"why not to enjoy life instead of spending 50-60 hours at the office?" is really selling short how much work raising young kids is. It is NOT enjoying life to stay home with toddlers. Maybe once they start school and you get hours to yourself, but before that it is way more time consuming than working at an office.
I know, I have done both. I took long paternity leaves to care for both of my kids, and while I love being able to bond with the kids, I was so happy to be able to go back to work. The freedom I have at the office compared to being home with the kids was night and day. Just being able to go to the bathroom when I need to, to get food when I want..... young kids are non-stop work.
I LOVE being a dad, but the weekends are way more stressful than the weekdays. Wrangling kids is way harder than programming computers.