But consider as just one example how much the population working in agriculture has decreased over time - much of that was going to happen whether roads and bridges and power lines were subsidized to go out there or not. When this is private investment, it's fine. If it fails, some company goes bankrupt, life goes on. Unwinding money-losing public infrastructure is much, much harder.
The last paragraph, that renters aren't politically invested, I think depends a LOT on the ability of people to become owners in the first place. Ownership is more the effect of someone who has a certain amount of wealth and stability in their life (thus the resources and desire to own), rather than something that CAUSES wealth and stability in your life.
So as for the idea that "the country was founded on the idea of the homeowner," I understand, but I think we have to be careful not to think that it somehow makes an owner morally superior to a renter. That just leads to discrimination against people who probably would love to own but don't have the resources, and thus don't need the deck further stacked against them.
For one thing, there was (and is, in, say, China now (can I get some more commas in here?)) massive inequality between the wealthy, electrified urban areas and poor, low education, rural areas. This is a problem for a democracy like the US, where an urban majority (which only happened in 1910-20) cannot run rough-shod over a rural minority. That political problem is enhanced by a media who is certain to show the famine out in the sticks, in comparison to the comfort of your favorite city.
Further, all of the resources are in rural areas. You'd have a hard time digging coal out of Appalachia if every moves to Jersey City. And you still have to deal with agriculture: your bread is coming from the Dakotas and your corn flakes from Kansas. Unless, of course, there's no infrastructure to transport it from there to here. And this was before the "green revolution" made food really, really cheap.
There are also other factors. The US was largely founded on the idea of a homeowner, living on a homestead that he owns, with property rights and all that. And then there's the belief (which I kinda agree with) that people who own property are more involved in their communities than people who don't, and thus that home ownership is a good thing in itself. ("The city council is doing something stupid! Do we go down and yell at people, or do we pack up the apartment and move?")