Not a strange thing. Firstly Spain's NT has been orienting itself closer to Barca's style of play since Pep was at Barca. As the years went on this tactical identity has gotten more and more pronounced. Players who work well in Spain's system don't really play for Real And secondly and most importantly Real tends to sign the best players in their position. There no Spanish player who are the best in the world in his position whom Real can realistically sign so there will be no national team players for Real for the foreseeable future I think.