Some narratives of the recent terror attack in Christchurch imply that even though conflicts, battles, and invasions among various warring empires ravaged Europe throughout its history, somehow the Ottoman invasion and regime is singled out as worse in the non-Muslim world as if Communist, Nazi, and Fascist Empires were somehow much better, or in other words, are more acceptable than the Ottomans. Also, genocides of Bosnia are not much talked about, as if that was not enough of a price for Muslims to pay.
This is like saying, "Even if he killed 6 million Jews or 2 million Ukrainians or a few thousand Bosnians, he is our homeboy. So, just forget that."
One point could be: Ottomans never either accepted or paid the price for their atrocities. They might have never accepted but neither did the Russians or Serbs or Croatians. On the other hand, Ottoman empire was invaded and split, and modern Turkey was a de facto ally of the Allied forces during the WW2.
It is not true that this narrative is limited only to some extremist groups, not the mass population. This is proven by going through comment sections of various social media platforms, news sites, and so on. Also, the rise in minority persecution in various developed countries.
So, my question is, What is the origin of this narrative?