Did you ever hear about the Armenian Genocide? You could fill books about whether or not the genocide part in that is justifiable or a dangerous anachronism. The Turkish government takes the nomenclatura so serious because they fear very real legal repercussions from the acceptance of the term Genocide. If the Armenian Genocide would take on a meaning similar to that of the Holocaust it is very possible that Turkish interests would be attacked (with possible) success in court all over the world. Formal apologies are just as explosive, and for the same reason hardly anybody goes futher than expressing regrets about excesses in the past.