People who don't actually look at facts, but at feelings they have do to patriotism, ethnocentrism, or other sorts of values don't really care about accuracy in labeling. They also don't like unacknowledged but horrible national acts brought up because it stains their sense of nationalism and machismo.
It was a genocide. There may have been awful things happened to precipitate it, but it was a genocide and the record is fairly clear on this.
It would take courage for Turkey to accept this part of their past, apologize for it, and show that they are big enough to accept the bad and the good in their past. But they aren't, nationally, and these hackers are an example of that.
Until you can be brutally honest with yourself about the warts on your nation's past, you can't ever really be a great nation. You have to be able to look your mistakes and misdeeds in the eye and say 'yeah, I own that... not proud of it.... and there were reasons.... but I own that'.
When and if Turkey can ever do that, they'll show they (as a country and Turks as a national population) have grown and are not so fragile as to need to hide, deny, and otherwise act like an ostrich in the face of their darker moments in the past.
Most nations have them. The number that have the guts to face up to them and try to accept the dark parts and maybe even do something to commemorate or make restitution are not that large. Turkey is hardly alone in living in denial.
Aren't we talking about something that happened 100 years ago? Something that happen so long ago that most if not all the people involved in it are dead? Not exactly sure what the pope had in mind saying it, but sometime the past is bet left in the past.