I do wonder if the situation has reached critical mass and that due to it being a unified culture which I think

Maybe the wrong word to describe South Korea and other similar Confucius Nations it won't find it hard to reverse the problem

I remember reading that those kinds of cultures also don't find parenting as enjoyable as people's from over places in the world

Don't quote me on that I don't have the source to hand but it sounds like one of many good explanations