I've heard he's a really good author but I've haven't read any of his books. Was he a private detective and an arson investigator in real life or were those the protagonists in his book?

I know what you mean about the hardcore dt supporters. My thoughts are that his supporters are either:
Cult members belonging to the cult of dt
Born with a difficult, unkind, hateful, or ill-tempered nature
Incredibly angry people who are energized by dt's horrific actions

Thanks for the input that you're apt to believe him. That's what I'm trying to get a handle on.