It is about time companies stop rewarding employees for time spent doing work, as opposed to results of the deliverables.

In SV there is a myth that employees that are young and single are somehow more productive. That might be in a cruel sense true for the founders, as you most likely have no obligations outside of your company and generally feel like spending 24 hours devoted to it, but for an employee, this notion is utterly false.

Plenty of married/parents spend unhealthy amount of time on their work, and plenty of single employees spend way too much time talking and playing games in the office, all to appear as if they are putting in the long hours.

Meanwhile, although parents certainly have a lot less "free time," you also learn to be very efficient with it. Talk less, do more, be more strategic, ..etc.

There is no one size fits all, and it's just lazy to say that one group is more productive than the other solely based on the factor of hours theoretically available to do work.