Baloney. The problem is that the regime in the North has set up essentially impenetrable barriers to people trying to leave. "Lack of Christian compassion" by South Korea has zip to do with it. There is this thing called the "de-militarized zone" (which is anything BUT) along the entire border between the two countries. Exactly HOW is the South supposed to set up an "underground railroad" through THAT???
Your "thesis" is laughable.