Let's compare the two most prominent examples on each side. The Armenian Genocide and the Jewish Holocaust.
The first, Turkey, denies to this day it ever sought to deliberately eradicate a minority community. The Turks refuse to admit guilt on the matter of the Armenians and no one cares, modern day Turkey basically being welcomed into the modern world by everyone and Hitler based his decision to kill the unwanteds partly on the world's indifference to the Armenian plight. In other words, Muslims did nothing wrong to the Armenians.
The Second, Germany, has enshrined in it's law that it is a crime to deny the Haulocaust. This event is admitted and remembered and a deep guilt is felt even to this day by Germany and perhaps the western world as a whole for what it did to this people (not only Jews mind you, but Poles, Romani and other elements that didn't fit in with the third Reich). Christianity is routinely blamed and Christians are at fault.
If you want to say Christians are guilty of Genocides, alright, we are guilty of genocides. Unlike the Islamic world, the Christian world can admit it's guilt in the past, it's flaws and hubris. I think it foolish to accuse Christianity of genocide however and not 20th century Eugenics ideology or a western Imperialism which was largely impartial to Christian Moral concerns. Who truly represents Christianity more, Hitler of Dietrich Bonhoeffer?