Because someone is giving them their lunch money.
Stop giving them food.
I know its not a popular solution, but at some point the North Korean government is going to have to divert resources from their military and destructive weapons campaign and pay for their own food for their citizens.
If you blame China, great, stop giving China ALL of the manufacturing that we used to do in the United States. It’s a win, win proposition. Its hurts the Chinese economy and it gives back the manufacturing jobs that were lost here in this country.
Its sound so simple doesn’t it ?