If your first priority is your kids, your first priority is not your work. That's fine, it's a choice, but there is a frequent claim that the massive incremental time demand of kids makes one so much more time efficient at work that it more-than-compensates. Insofar as one is the same human being, with the same energy reservoirs and time management skills as before your child was born, this is unlikely.

I understand the reason this fiction is maintained: people with kids need the job even more than people without, and have an interest in denouncing people who claim kids make you less productive. There's also the second order effect in which "with kids" is correlated with "older".

The net of it though is that devs with kids tend to assign work a lower priority, to take fewer risks, to need more money, and to be older and hence less familiar with new technologies (and too busy to learn in their free time).

Society doesn't have a good answer for this situation yet. In times past, technology didn't move so fast that experience was mostly obsolete (and hence useless) in a decade's time. A 40 year old farmer with kids in 1713 would probably have much to teach a young whippersnapper. The same isn't true for a 40 year old programmer with kids in 2013.