[AngryData]

Because current economic policies and capitalism rely on a continuously expanding economy. If the population grows, the economy will continue to expand, if the population doesn't grow then much of the capital class starts to lose money on investments that never materialize.

It is not really a problem for the regular working class citizen, and historically population drops have improved wages and labor rights. See things like the black plague or wars with large casualties, which resulted in significant population drops which gives more power and leverage to the labor class.