Small family farms are good when a country is still developing and has excess labour, but once industrialization gets going folks move to urban areas for factory jobs and farms need to consolidate and mechanize. This has been the story over history for all countries have been 'developed', and in the post-WW2 is generally true of Japan, Korea, and Taiwan. Though this mechanization never really happened in Japan.
How Asia Works: Success and Failure in the World's Most Dynamic Region goes over this quite well: