He doesn’t want his kids to end up where he did, so he’s literally sacrificing himself to give his kids a chance in this world.
I think this quote as Evgeny Tchebotarev wrote pretty much nails it. This mentality is pervasive in Asia. My father said the same thing to me and my brothers when we were young (we are Filipino Americans).
We can ask the same question about why families live in mountains of garbage dumps all over the world making a living out of collecting rubbish. I lived with a young Balinese family that worked on a cruise ship. They came home for a couple of months to have their baby. Then off they were, back to the ship liner for another six months. So the saga continues around the globe.
Thanks for asking.