I’ve never been that far to the south but lately I’ve been reading and watching those novels and movies.
The prevalent idea is: in this world (Texas?) you are alone, nobody gives a cr*p about you, do not trust anyone because they’ll take advantage of you, ridicule and mock you. The world (or maybe only Texas?) is an inhospitable, inhuman, Darwinist place.
I love Texans but when I worked telephones when I was younger, only the most awful people were exactly the kinds of Texans you’re describing. Maybe it was because we were strangers but there is a part of me that’s still terrified, especially of Dallas people, because of it.