Before I get to the particular facts, there is more than just a factual problem here. There is a theoretical problem as well and I tried to make the point that we must distinguish between what an individual or group of people do and what the code that they allegedly follow actually asserts. The fact is that there are people who do things consistently that are inconsistent with the code that they allegedly follow. But often times when that happens, especially where religion is concerned, the finger is pointed not at the individual who is choosing to do something barbaric, but at the code he claims to represent. The only time it's legitimate to point to the code as the source of barbarism is if the code is, in fact, the source of barbarism.
People object to a religion that used barbaric means to spread the faith.
But one can only use that as an objection against the religion if it's the religion itself that asserts that one must do it this way, as opposed to people who try to promote the spread of the religion in a forceful fashion in contradiction to what the religion actually teaches. It's my understanding that much of Islam has been spread by the edge of the sword. That isn't because Muslim advocates were particularly violent. It's because their religion actually advocates this kind of thing. The difference between that and Christianity is that when Christianity was spread by the edge of the sword it was done so in contradistinction to the actually teachings of Christianity.