What's There?

I recently moved across country, and as I spent two days driving from LA to San Antonio, one question kept worming its way into my head as we passed through every small town.
   What's there?
   I mean, I can see that there's a Wal-Mart (usually), and gas stations, and schools and a police station, all the kinds of things that you need when you have a certain number of people living within proximity to one another. But I couldn't see what keeps those people there, aside from a particular inertia that we human beings have with regards to our homes.
   Why are certain small towns still places on a map? I know that, in days past, small towns sprang up at trail intersections, or at rail heads, or around natural springs, that kind of thing. If you're traveling cross-country by horse, you're going to need to know where to get water. A lot of water. And if you're herding cattle to load them on box cars, it helps to have services around where the train stops. When we tamed the West we needed a lot of little towns strung out along trails and roads and rail lines.
   But now... not so much.
   I understand that a place like, say, Deming, New Mexico once had a reason to be there, but now it seems to me that the jobs in Deming are geared towards the people of Deming. That is, the Denny's, the supermarket, the insurance broker, etc. etc. Businesses that are there because the people are there, rather than the people being there because the businesses are. The difference is important.
   In the last 50 years we've seen a grand shift from rural to urban living in the US, but it seems to me that the reasons we have a lot of small towns no longer make sense. I can see that the steady urbanization of America will become a grand urbanization, with people moving to manufacturing centers and service centers, which are the big, sprawling cities we now have. Which will only get bigger and sprawlier.
   What does this mean for a place like Deming, New Mexico? I don't know for sure but I can guess. Probably the same thing it means for Luling, Texas, or for Emmett, Idaho: a slow decline as their citizens move away, either to big cities for pointless jobs they'll hate, or back to the farms and ranches where they once labored.
   I think the small town is going away. At least until the cycle turns back around.
   Now... if you could harness the labor force in these small towns, and actually start making things in the US of A again... maybe you'd have something. Food for thought.