Failure seems to be on management for not allowing the people with families to flex their work schedule and work outside of normal hours. Or is this a specific example where the individuals are not able to perform their duties outside a specific window?

As the parent article was specifically about Tech firms, I find the likelyhood of a position with rigidly fixed hours low.

Anecdotal, I know, but I work in the tech field, and am a parent of two small children. Luckily, I've been given the ability to flex schedule, and often work two or three hours "after-hours" if I needed to go afk to parent during normal "office hours". I'm rather confident that my productivity has not dropped by any measurable margin since my flex scheduling has started, and has probably increased, since I more often take on late-night deployments or maintenance tasks since it allows me to trade hours for day-time parenting.

Now I'm sure there are people who are taking advantage of the system, or perhaps are unable to flex or work after hours and may be unable to shoulder their full workload, but I think that group is being blown out of proportions.