Do you really think such folks could ever be productive contributors to this site?

They can be, but it's not worth trying to seek them out. Correct me if I'm wrong, but didn't lukeprog have pretty serious Christian beliefs at one point?

he cannot accept any perceived challenge to their preferred theories

I find your mismatched pronouns painful.

I think it makes a big difference if the preferred theory is gender/racial equality as opposed to fundamentalist Christianity, and whether the opposition to those perceived challenges result from emotional sensitivity as opposed to blind faith. At the very least, the blog post doesn't indicate that the author would be irrational about issues other than marginalization.

This person actually states that he cannot accept any perceived challenge to their preferred theories.

The "preferred theory" in question is that they are of value as a human, and that they have considerable experience of being treated as not of value as a human, up to and including violence. As preferred theories go, this strikes me as not being an unreasonable one to hold.