No silly: in post-Christian Europe, people have no duty to either G-d or each other; such people live for themselves and indulge into pleasures.
This is an insightful article, although I have the same quibble as you. People had children during the centuries when life for most of us was "nasty, brutish and short." People in Europe are deciding not to have children because they are secular, materialistic, narcissists.
But the great point this article makes is the impact on the economy when population growth drops past replacement. Two thirds of the Western economy is dependent on consumer spending. Consumer spending is fueled by young and middle aged adults, who are in the acquisition phase of life and many of whom are raising families. Older and retired adults tend to live off the assets they acquired earlier and spend much less on consumer goods. This trend has hit Europe, Japan and European-Americans. Immigration (and the State of Utah), however, have kept America much younger demographically, which fuels economic growth.
I'm really surprised no one has linked the interminable Japanese recession or the stagnation in Europe to the problem of their greying populations. OK, I guess it's not so surprising since liberal CW says the problem is overpopulation and they haven't come to grips with the fact that population growth has been slowing since WWII and according even to the UN will peak worldwide in 2050. Liberals are always playing catch up with the facts.
This writer skipped over one of the major reasons why people have children: a sense of obligation and loyalty to their culture and people. Socialism has convinced europeans that they are atomized individuals whose only loyalty is to the state. As such, they live their lives as if their only loyalty was to themselves and to materialistic consumption.
Healthy "tribal" cultures place a variety of carrots and sticks in front of their members to procreate so as to ensure the survival of the tribe. Without this motivating force, people naturally follow the most convenient and hedonistic path....and live their lives accordingly.