I grew up in a small state called New Hampshire in the Northeastern part of the USA. There people used the term "rednecks" or "hicks" to refer to those local people in the countryside that often: drove around in big jacked up trucks, chewed tobacco, shot guns, drank canned beer, wore steel toed boots and/or who were not particularly educated or worldly.
They had a regional mindset that didn't extend beyond the limits of the town. Their mindset was conventional, traditional, conservative, local and ignorant. If you were different then you were subject to ridicule as they weren't open to new ideas and experiences.
However, I have realized through all my travels that these kinds of people exist all over. At least in most places that I have been to or lived in. It's a mindset that fears outsiders, something different or upsetting the status quo.
For example, in Taiwan they may wear a different mask. There they wouldn't be chewing tobacco, but they might be chewing betel nut instead. They don't drive big trucks, but they might be driving a scooter that's been souped-up and that has a muffler that is extra loud.
Rednecks do not typically have the best manners either. In China, you may find "rednecks" spitting and hawking frequently on the street or even staring at you. You might even see a "redneck" in China do a "farmer's blow". The funny thing is that in China a large percentage of the huge populations found in cities like Shanghai or Beijing contain Chinese from the countryside or much smaller cities. Many people, not only in China, are moving to the city in search of a better life.
So even if you are not living in a big city chances are you are going to run into a redneck of sorts. A person who has had little exposure to things, ideas and people outside of their native region. They're people who are living in a smaller bubble. Travel and the experience of living abroad amongst people of different cultures does make ones world view and bubble larger.
It's impossible to know and be aware of everything. We all live in a bubble of some size or kind. I suppose the term redneck or rather ignorance doesn't just refer to people from the countryside. It's an urban phenomenon too and I also meet so called "educated" people who are ignorant.