By subsidizing rural/suburban living we encourage it and thus people waste more time commuting, wasting fuel, increasing traffic, requiring more subsidies (larger roads) and so on.Interesting that you would pivot from a pro-market position into a social engineering one. Those two usually don't go together.
Look I've paid for the T-1 line to be ran 200 miles so I could have high-speed internet -- and I did this back when you could count the number of T-1s in my area on both hands. So I don't mind only having those who can afford it pay for it.
But I also understand that this country is huge, and spread out. And I don't want to encourage people to live anywhere. If you asked my druthers, I'd want them staying at home in rural America, on fiber, and living more of the agrarian life that the urban one. But that's not the point.
The point is that the community as a whole has a vested interest in infrastructure: roads, power lines, and communication. It's the same argument as national defense: government does really badly at some things, but there are some things that it's the only effective player to pool resources and common interests. That's not a license for socialism, that's just saying that a piece of wire to every home -- phone, power, or internet -- is a political issue much like how many aircraft carriers we need. If we left it up to individuals to decide the response wouldn't be uniform enough, and uniformity is the one requirement that these attributes need to have.
Communication and electric power aren't like pork bellies and automobiles -- they are extensions of our powers as individuals: our power to innovate, collaborate, discover, and create. Hell, it's more like gun ownership than buying pork-chops at the supermarket. They are a hell of a lot more critical than health care or consumer protection.
I'm absolutely for a maximized free market. But the argument here is that limited communication abilities reduces information in the market, stifles innovation, and limits choices. That's why I chose the greater freedom of universal high-speed connectivity -- not as a government bureaucracy, but as government defining the markets so that all the players meet all the needs.