I hope you're just really misinformed and not just really racist but you should take a quick stroll to your local library, buy a few history books and look around.
Christianity has been far more brutal and repressive for a lot longer than pretty much every other religion out there.
Which doesn't change anything in the conversation that started about "the Islamic world" being built on the conquest of more civilized peoples, which were mostly Christian.
Also I'm fine with reducing Christians to "middle-eastern Christians" here. Others don't seem really Christian from there anyway. For these reasons as well:
King Leopold murdered ten million Congolese. The British empire 100 million Indians. The dutch started the slave trade.
Only I think the Portuguese started the slave trade. Not that it changes anything.
I know what I'm talking about, but I get furious over Westerners trying to find indulgence for their own ancestors' actions at the expense of Middle-Eastern native Christians, and I see saying that Crusaders were somehow worse than any Muslim conquest as part of that.
Being furious I may sometimes say something imprecise.
Doesn't negate the fact that Islam is not native to any place outside of the Arabian peninsula, and those areas it has invaded still have native populations and religions not yet completely exterminated, and those are largely Christian. Saying that Crusaders were the baddies, but the Muslims whom they were fighting were not, is disgusting in that context. It's like that "Irish were like slaves too", putting things into American context so that you'd understand better.
Same as that myth of Salah ad-Din being benevolent and honorable, mostly started by German Empire's propaganda as part of their relations with genocidal Ottoman Empire.