Greedy, selfish? Maybe they figure kids are too expensive to raise. There's lots of people here who bought into that notion, except here they have the sex and then kill/abort the babies.
Japan has a set of regional/county borders that allocate votes. The farmers in one county may have up to ten times the representation of the city voters.
And one of their actions has been extreme protection of the Japanese agricultural sector - including preventing construction of housing on agricultural land.
I met a ham radio operator from Japan who explained you could either have a wife and kids or a ham radio room in Japan, unless you were rich to have both. Housing is UBER-expensive for many Japanese as a result, which has a contraceptive effect. You might manage one kid in a rabbit hutch apartment, but not two.