Read a book then come back and talk.
Hell, there's a number of outstanding television shows with neat CGI animation that tell the tale, OMG ONE WAS EVEN HOSTED BY ROBO COP! Get informed on the past before you compare it to the present that you've have indeed observed.
You can't just say "Crusades me all you want...." and expect to avoid the subject. It'd be like saying "Ignoring that whole WWII and Holocaust shit, you can't fault the NAZI's for much.
".....but you don't see Catholics rioting and bombing shit." Because they didn't have bombs. Do you have any idea how many outright massacres there were during the crusades? I mean "Hey, women and children, come hide out here during the battle and you'll be spared... ok, battles done but I'm still feelin' stabby, c'mere!"
Christendom has indeed taken on many campaigns centered entirely on wiping out societies and replacing them with their own. They utilized every tool of pain and suffering that was available to them, including biological warfare.