While I personally am not qualified to answer your question, these comments in past threads discuss the details of Turkey's opposition to calling the Armenian Genocide a genocide and why Turkey is defensive about the subject even though it was the Ottoman Empire which committed the act.

This answer by /u/yodatsracist

This answer by /u/GekkostatesOfAmerica

And this answer by /u/shaikann

Always more that could be said, but you might be interested in these past answers:

• Why does Turkey deny the Armenian Genocide so Vehemently when it was committed by the Ottoman Empire, not modern Turkey
• The History of Armenian Genocide Denial
• The Armenian Genocide: Why is the current Turkish democratic republic so defensive about something that was the fault of the Ottoman Empire?
• How should I, as a Turkish citizen, educate myself on the Armenian Genocide?

There's also a section in the FAQ on the Armenian Genocide which includes responses to similar questions surrounding Turkey's denial of its existence.

Almost exactly the same question has been asked before and several users posted good answers including u/GekkostatesOfAmerica, u/shaikann, u/jman12234

I want to offer one more reason not directly stated by the others. Nationalism of the French way.

During his formative years Ataturk spent some time in France and came across the French version of nationalism: the policy of one nation, one people, one language. France employed a strong unitarian government without giving any power to the provinces, forbid the use of all languages besides French (which led to a dozen of languages in France to become functionally extinct). This system is still in use in France.

This was adopted for the new state of Turkey. The country had next to the Muslims two more peoples which were constituent peoples: the Greeks and the Armenians. At that time, a people was united by their religion and not by their language. They wanted to create a country that was not pluralist. The Greeks (even those who spoke Turkish as their mother tongue) were deported to Greece under the agreement of population exchange with Greece. And the Armenians who were decimated just a few years prior proved an opportunity that couldn't be ignored to not deal with them any more. On top of that, the Armenians were still the "backstabbing" scapegoats for losing the Balkan. An apology or official acknowledgement would jeopardize the new emerging nationalism.

This new nationalism consolidated and led to further attacks against Greeks and Kurds (who were now to be called Mountain Turks).

A thaw never happened.