Well, then focus on the geology. Cyprus is part of the continent of Asia. Whereas Turkey is partially located in Asia and partly in Europe.
Of course, there is some inconsistency. Greenland would geologically be part of North America, but it counts toward the European map on project-gc. And Iceland, like Turkey, straddles two continents, Europe and North America, but is only listed on the European map. And both Sicily and Malta are on the African continental plate, but Ceuta is on the European plate.
But now this has devolved into an exercise in pedantry, I'm afraid! :) Therefore, at the end of the day, I suppose it's easier to be a little arbitrary about it.