Things like family and child-rearing increasingly are inconveniences in our driven capitalist society with our consumerist mindsets, to the point where it never "makes sense" for anyone to do it at all.
There are many things about being parenting and family that inconvenience me. But I would never consider being a father or a husband an inconvenience. Nor would I say it "never makes sense" for people to do it. For me and Mrs. Cool, it made all the sense in the world, and I would bet a large percentage of parents would feel the same.
I agree with you, and feel the same. But think of a 22 year old today. Our society increasingly stigmatizes anything but putting the most of one's self into one's career. The same goes for women as for men. Fewer and fewer people grow up thinking that starting their own family should be a priority in their life, because there is nothing socially driving that message any longer. In fact you often hear the opposite, people being judgmental towards those who have children too soon at the expense of their careers or when they're not perceived as being well-off enough. People constantly say that "life is over" when you have kids, and they are talking about your ability to focus on your career, hang out in bars and clubs, spend lavishly on yourself, etc., very rarely do you hear someone saying that life begins when you have kids, which is more or less the way I felt about it once it happened for me, at least in terms of how it's changed my life and perspectives.
My point with regards to the OP was to say that if we, as a society, value the continuation of our species while also simultaneously being totally unwilling to let go of this driven, capitalist-consumerist way in which society is ordered, there have to be some support measures so that people can do both. We've seen what's happened in Japan, South Korea, and Taiwan, among many other places, when those support measures do not exist. Employers not discriminating against those who have or would like families is one possibility that I'm sure has kept a lot of us employed when we wouldn't be otherwise under some more cynical system that does not value at all the continuation of life, and there are many more support measures worthy of consideration.