Well, they one quite often. For those of us old enough to remember the Olympics when East Germany and other socialist countries dominated it's tough for amateurs to compete with Government sponsored systems where people are recruited by the 10s of thousands and their full time job is to train. Then from those 10s of thousands you get the couple dozen elite athletes. I recall a referee meeting before the 1997 Championships where a 4th Dan from NK was used as an example and he did patterns which were critiqued by the Seniors and I am thinking "Heck, looked pretty damn good to me." He went on to win the gold. Another NK athlete took the Gold for the Turning (roundhouse) Kick set at 9'7". They bordered on the superhuman. But then again that is what helped General Choi spread TKD in the 1950's and 1960's . He recruited top talent nicknamed the Korean Supermen and they went on demo tours.