At that time, the Ottoman Empire was in an existential battle for it's very existence and those who dispute the Armenian genocide believe both that wide scale violence, persecution and murder was motivated, in part, by waves of ethnic cleansing committed against the Ottoman Empire's Muslim population in the Balkans and the Caucasus.
The victors write the history books. The Ottoman Empire was crushed as were their leaders and the Empire chopped up and literally eliminated by the victors. Who wrote the history from their perspective? No one. Just like history screams of German atrocities but largely is silent about Russian mass atrocities prior to and during WWII. Does that minimize the Nazi holocaust? No. But it doesn't mean the Russian atrocities are irrelevant either.
When wars become wars of national survival, unfortunately war also becomes increasing mass atrocities. Out of blame. Out of retaliation. Because everyone of them is the enemy - often due to escalating guerilla warfare by those being persecuted - for which then ALL civilians are potential enemy AND a desire to not have those people take the country if you lose.
The battle lines between both the Germans and Russians - and Japanese and Chinese - became kill and rape everyone, burn everything. Since some civilians do support, feed, hide and house guerilla warriors - and are a source of guerilla fighters who won't wear uniforms, those civilians in toto come to be seen as the enemy - why the often are put into concentration camps, deported, large numbers murdered publicly to make an example, and such.
WWI and the wars prior to it could be described as wars of atrocities. So there not only is the question of whether the Ottoman government directed a genocide against Armenians, but also whether then it was the largest genocide of all those going on?
At some point, wars of survival on a mass scale become revenge for revenge and retaliation for retaliation. All of them trying to kill all of us and visa versa. Civilians become quasi-military because their civilian activity and mere existence is a source of the enemy - if just a source and support to guerilla warfare such as the French Resistance as an example. Did the French Resistance kill every German they could in France, even if just in a civilian German administrative role? Were they murderers for doing so? Did French who fed and hide those fighters make themselves a military enemy?
And terror is a recognized tactic of war - for which nearly all bombing by the Allies for a while was against German and Japanese cities - ie fire bombing "to break their will to fight." Genocide? Mass murder? Or how wars go?
Is the side that kills more successfully then more evil? Is the loser more evil? The winner? Is it measured in motivation or body count?
We forget that historically in the further distant past wars tended to often be about genocide. The GOAL of the war was to kill everyone of "them," the other people, and take their land for yourself.
All of the USA came into existence under that premise, didn't it? Kill or run off all "Indians" and take all their land. That is what MOST wars in the past were about. Get rid of them, take everything they have. Do Americans throw ashes of remorse on themselves? Any of you care to give everything have back to those people? Your house? Car? You don't even think about it.
The "Biblical" style wars, in which exactly everyone except those taken off into slavery in a city-state would be killed - as in everyone.
The notion of ANY morality in war didn't largely come about until the late 1800s and evolved slowly.
AND THAT IS WHY I ASK WHY THE FOCUS ON THIS PAST MASS ATROCITY? There are hundreds to pick from. Thousands, depending how far back you want to go. Why not talk about CURRENTLY RELEVANT atrocities instead?