No one in Turkey denies that lots of folks died horribly during relocations during WWI. No one disputes that there was a "Trail of Tears." What is disputed is the allegation that there was a politically mandated, bureaucratically administered policy of mass murder, which is what genocide actually is.
When everything becomes genocide, then nothing is really genocide, and the word becomes mere grist to be ground in amy ideological mill. In this case, the large numbers of Turks killed in the same period in the same manner are ignored.
Taken together, all this tells me that the word genocide is thrown around for the emotional connotations it creates, instead of an accurate description of what happened.