By "requiring" I mean in terms of social expectations, not government laws. Many policies, e.g. lunch breaks, are "required" by social norms, not law. (Only a minority of states require lunch breaks; bathroom breaks are not required for the most part either: https://www.lexisnexis.com/legalnewsroom/labor-employment/b/...) E.g. Most tech companies offer far more than the minimum FMLA required leave. That reflects "'values' that employers come up with voluntarily." That's also based on social expectations--a tech company that only offered the legally required minimum leave would get a lot of bad publicity for violating social norms, even though it would be legal to do so. Finally, it's not "discriminatory" even though childless people can't take advantage of such leave.