Think about it. They aren't really trying to convince anybody. Dan is spouting the nonsense of "repentence comes before knowledge." Norman is perpetually antagonistic, and in denial of reality. Currently, he is claiming that Hitler was not a christian based on an apologetic site that is manufacturing quotes. It's a little like the "deathbed conversions" of atheists only in reverse. A christian says that someone said something that no one can verify. But, understandably, christians don't want Hitler among their ranks.
Now, some people might simply think that fundamentalists are stupid or crazy. I do not. Oh, I'm sure that those elements exist. But I think there is something more sinister at play. Christians want to be able to tell people "you had your chance." If they presented their message in any plausible manner, they might win converts. And they do not want that. That would take away from the "ha, ha, you missed out" factor. They want outsiders to dismiss them. Now, I still think that they are wrong. But I also think that any god that would support this kind of behavior is evil.