is there any other case of this in boxing , where a country consistently produced boxers of a fairly high level, only to have a completely dead scene like a decade or so later?
its not just that the south korean scene isnt as strong as it once was, it's now basically non existing! they used to have plenty of world champs and world ranked fighters
The economy and tragedy. The economy grew insanely rapidly and deaths to a number of fighters further put Korean boxing on the shelf. Things haven't been helped by boxing politics (they had 4 or 5 different national bodies).
Some decent fighters emerging now, though it's a shame Min Wook Kim retired
Other sports have increased in popularity, the gaming industry development, but as has been mentioned, arguably the economic impact has had the most influence.
Having spoken to many work colleagues over soju (I have lived and worked in Korea for 15 years), boxing was a poor man's sport, for those seeking a better life (the same in many countries?), but with the economic miracle of past decades, people have been able, or seen a route to a better life through business, think careers at Samsung, LG, Hyundai etc...
Also mentioned by my colleagues, is the hierarchy system, or 'class' if you like, which has a smaller impact. There is perhaps a slight 'stigma' attached to being a boxer. You'd be viewed as poor or lower down the hierarchy in Korean society as a result. For many Koreans, how you are viewed by others is of concern or even of importance. My wife often worries about how others view her. 'Keeping up with the Joneses' is the be all and end all for some here.