Only Argentines Tango?
It might seem strange that Asian dancers dominate Latin dance competitions. The same could be said about a tall skinny redhead kicking ass in martial arts.
Who are we to close off practice and/or competition of dance, of sport, to anyone? Even Islam, Hasidic Judaism, and Buddhism take converts. And these people have changed their lives in similar ways in order to master the craft, devoted time, effort, and quite probably, adopted a love of the dance.