Re: the Alabama bar, when that same criticism was leveled by Neil Young, the response was, "A Southern man don't need him around anyhow". Apart from the fact that it came in the form of hit song, the reply is notable in that it's not something along the lines of, "them's fightin' words!" Though you may be right about the South's religious and political attitudes, I think you misunderstand how and when violence is used in that culture.
Anyway, back to the issue. The mindset of Mohamet Atta, et al, was elegantly described by Eric Hoffer in The True Believer. I don't believe it takes any unusal emotional insight to understand Atta's psychology, if it's seen in those terms.