It doesn't make any sense when you go into the analysis with preconceived assumptions. If you break out of the bad assumptions its fairly simple to understand why the average Confederate soldier fought.
A New England blue-blood brings his Souhtern Belle fiancee home for dinner.
The Belle asks one of the female dinner guests "Where do y'all come from?"
The woman coldly repies "We come from a place where we don't end a sentence with a preposition".
The Belle responds, "Oh, I'm terribly sorry. Where do y'all come from, bitch?"