He means not important for the political and economical system, not literary useless.
Better than that; by transferring a bit of money from taxpayers you can account for wages from 2 paid jobs, the mother's and the carer's.
There is a sort of neoliberal logic to it of course; in early childcare in my country, ratios are 4:1 - there is an "efficiency gain" if the mother earns more than childcare fees for the children under care.
But of course childcare availability is certainly not a bad thing even if there might be agendas in play.
To generate future GDP (and thus tax revenue).