Why don't talented central midfielders emerge from Korea?

Lee Kang-in is an attacking midfielder, and Park Ji-sung is certainly far from being a specialized central midfielder. We produce world-class attacking lines like Son Heung-min or outstanding defenders like Kim Min-jae,
but why can't we produce top-class central midfielders for the major European leagues?
Even Ki Sung-yueng, by my standards, wasn't a top-class EPL central midfielder, so it's a bit disappointing.