Statistically, Asian women are more likely to marry interracially than Asian men (graph from this article). Additionally, while 11% of all intermarried couples involve a white man and an Asian woman, just 4% of couples include a white woman and an Asian man. Those stats are all from the US, but it’s still interesting.

In other words, it’s not unique to kpop idols, but rather is in-line with the statistical trend.