A lot of people do it, you just don't hear from them. The media and popular culture pushes the idea of city living very hard. I have some theories as to why, but they're not appropriate for this venue.
In any case, I'm one of those who lives in the countryside. I grew up out here, went to college, spent a few years kicking around various cities in the US and Europe, lived and worked in the SF bay area for about 5 years then moved back to the countryside.
I don't see it as "less" at all. In fact, I see it as more. What can you do in the city? Restaurants, movies, theater, concerts... it's all consumer behavior. If you want to produce something physical, that requires space, tools and materials. I will admit, getting materials in the city is much cheaper and easier than in the country, but you pay for it in the lack of space. My time in the bay area was extremely frustrating because I didn't have the space to tinker.
From a job perspective, I work freelance remotely while I build up my app empire! :) If you're not a programmer, then finding new employment is a problem out in the country for sure. Most of the people I know out in the country who aren't programmers and are doing ok financially own their own businesses and provide services to their neighbors. Lawn care, snow plowing, glass replacement, plumbing, contracting, carpentry, electrical, HVAC, embroidery, screen printing, accounting, lawyers, dentists, etc. There are unique entrepreneurial opportunities in small towns because there's so little competition. When something needs to be done in a hurry, some people will pay extra not to have to drive an hour or two to the nearest city to get it done. One guy I knew made a mint being the only skateboard retailer in 100 miles.
From a people perspective, there's this impression I get from city folk that country folk are stupid and if they had a room temperature IQ they'd relocate to the city. This couldn't be farther from the truth. There are lots of brilliant people in the country who stay because they like being close to family. They cherish the interpersonal connections they've made over a lifetime and are unwilling to throw them away. For better or worse, people are a commodity in the city. Most people don't spend a lot of time making deep connections because there's always somebody more interesting around the corner. I find it an exhausting and incredibly lonely way to live.