I think the great powers had more to do with it than that. The Yugoslav region was right at the line between the Ottoman and Byzantine empires, and the Catholic world of the west. The great powers spent centuries turning that region into an elite military culture dedicated to defending against the other side. They stopped the Mongols (or at least the Mongols mysteriously turned around there and went home), they stopped the Turks and they stopped the Russians. And then when Tito was gone, their natural state was to go back to war due to centuries of tradition.