You are wrong about her remark being a joke. When she initially made that statement she was perfectly serious and she caught a lot of flak about it because she was serious.
Ah, but the Muslims do accuse us of being Crusaders! So, she pressed the matter with an ironic vengeance. She is always indulging in this kind of flamboyant irony, I might add.
If she was kidding, then why was she canned? Because most people, even most conservatives, do not have a Christian's sense of irony. And most people do not like aggressive Christianity--even rhetorically aggressive Christianity.