To be honest, I'm not entirely sure. Past experience should lead me to expect at least a few non-Christians to post in defense of Christian guilds, but I have a habit of expecting the worst from people--and there's always at least a few people who deliver on my expectations with rude, antagonistic, and hostile posts.Just wondering why you are "consistently surprised" by non-Christians defending Christians?
I see so many disrespectful online trends like "Jeebus" (thanks Simpsons; not only did you stop being funny after season 10, now you're blasphemous), "Zombie Jesus," and the Flying Spaghetti Monster. (One could argue that the FSM is satire of organized religion rather than Christianity, but the "ha ha, you're stupid and I'm going to make fun of you" attitude does nothing to further constructive debate on either side.)
Flying Spaghetti Monsters aside, my experience online has shown that public forums tend to present a completely inaccurate picture of people's views toward faith in general and Christianity specifically. Forums are overwhelmingly disproportionately comprised of people wanting to rail on faith, religion, and Christianity, whereas the majority of America is either fond of or indifferent toward Christianity.