Even more importantly, there's just a lot of people in China. New York City's population is approximately 8.8 million; that is the scale of a mid-sized Chinese city. The population exceeds 1 billion, which is difficult to comprehend in terms of scale. The reference I like to use is: 1 million seconds is ~11 days, whereas 1 billion seconds is ~31 years.

To put it bluntly, China quite literally doesn't need (nor wants) the average software dev on HN. The immigrants they would likely want are those with expertise in much harder technical disciplines (semiconductor R&D etc.)