The reason it takes so long to get to Europe is the same reason that US sometimes doesn't even get some games. They want to make sure people will buy it. If not enough people buy it in Japan, then it usually won't get released anywhere else, and if US doesn't buy enough, it probably won't go to Europe or anywhere else. It might come to US first because we're closer. Japan and Europe are on almost complete opposite sides of the planet.

My thoughts^.