The short answer: it's satire.

A longer answer: The previous Dodge book (Reamde) had similar characters (rural, libertarian, gun-toting individualists) that ended up being crucial to the story. I suspect that Stephenson has a fondness for such people, and tends to think that they have tough skins, and would probably be amused by this send up instead of finding offense.

At least that's how it comes across for me.

I'm just starting this book, but knowing this writer; you can probably expect that wherever characters start off at, they'll end up somewhere else in the end.

EDIT:

OK, finished the book. The section the o.p. mentions is really just a tiny scene. It's so weird, because it really has nothing else to do with the rest of the book... or anything.

One of the books characters is hanging out with some friends. They decide to stop by and see how the dumb hicks live. They stand around talking about how "Princeton people" (meaning the brainy elite" are so enlightened, and these backwards hicks are so dumb and dangerous. Strangely, the dangerous dummies don't hear or take offense. Then they move on.

So weird. The scene seems too silly to ever be offensive to anyone though. But it did come across as so naively snobbish, that the "Princeton people" seem to be equally big fools as the ones they're looking down on.