It costs a lot to have infrastructure (hospitals, roads, power, water, etc.) across the country. I wonder if this is one of the long (long) term effects of moving from an agricultural, to industrial, and then knowledge economy.
It absolutely is. All these rural communities only existed in the past because there was an economic need for them, usually because of the mining or agricultural industries. The mining industries have dried up in many places, leading to "ghost towns" (this was happening back in the 1800s), and agriculture these days doesn't need nearly as much labor, so there just isn't much reason for many of these communities to continue to exist without some new industry to support them. So people are moving away to other places where there's jobs. This isn't a new story; it's been happening for centuries, or even millennia. But now, all of a sudden, people are bemoaning it for some odd reason.