Some people that reside above the Sweat Tea Line don't understand manners. It confuses them.
That and cowboys that far north tuck their jeans in their boots. This gives them somewhere to put the sheep's back legs.
Oh, I am so glad I had sat my coffee down before reading that.
What little experience I've had from being in the Northern clime, I think a lot of them just aren't all that friendly and don't want anyone to intrude into their privacy. That said, the clerk in the hotel/motel should be the type of person that is friendly to all.
And, in response to the lady that says I don't need to hold a door for her, I usually respond with "My mother taught me manners and even though she is gone, if we meet in the afterlife, I don't want to encounter her wrath."