A more benign explanation is that the community is reacting to two big changes. First, the economy collapsed six years ago and while improving is unlikely to ever recover, and more and more young men are (responsibily) reluctant to get married and start a family until they have the means to support them, meaning men will marry later. Such developments are natural and hardly earthshaking. Even for families with a tradition of becoming professional scholars, the economic decline affects them indirectly since the donors who finance the yeshiva world are less well off.
Second, we are finally adjusting to the fact that prior to the mid-20th century, we have very high infant and maternal mortality, but this radically changed in the mid-20th century (invention of anti-biotics, defeat of the Nazis, etc.), and there is less pressure to have as many children as possible since now, unlike a century ago, we can reasonably expect that all the mothers will survive their childbearing years, and almost all the children will reach adulthood. There is less to worry about. In all cultures, family patterns take a few generations to shift when these changes occur, and due to the holocaust the decline in child mortality (of which anti-semites were a major factor) occured somewhat later.