The problem with bemoaning this trope is that, in reality, there are myriad pockets of the North American population that literally correlate to many of these espoused characteristics - I personally come from a family rooted in rural New Brunswick, with ancestral connections to settlers that landed at various points along the Eastern seaboard and all drawing descent from the hills and rural areas of mostly Scotland but Ireland, Wales and norther England too. There is a distinct vernacular, an identifiable accent, a commonality of folklore and values packed into the steamer trunks that escorted their progenitors' passage to the New World, wherein the vast and various isolated, yet periphorally connected, diaspora gradually customized (basterdized) to suit their more specially environmental niches.
While I was raised external to the heart of my particular ancesteral perculiarities, I am well aware that I still am steeped in and am the direct product of this isolated cauldron, that in my tired or excitable moments, a discernaible accent sleps into my vocal cadence and a subtle peppering of quaint and geographically iconic jargon creeps into my syntax.
And yes, there is a degree of 'ignorance' - not in a perjorative sense but rather in the sense that most choose to remain connected to the geogrpahically homestead and limit their formal or further education accordingly. There are even slight whispers of the more antipodal position of 'suspicion' against those who separate from the familial 'roots' to pursue life in the wider landscape, encapuslated in folksy pronouncements 'Her head is so far in the books, she's lost her common sense' or "Now he's got soft hands"