50% population growth over 40 years is far from "crazy". Especially considering that most of the USA is empty.
We either need to reduce population growth, or convince politicians, voters, people looking to buy, and developers that just because we can't make a new hip metro area overnight doesn't mean we simply ignore all our available land (rather than continuously talking past each other on the issue of "we need more housing in desirable areas" vs "we need to not harm desirable areas").
Both seem like impossible tasks, depressingly.
It's significantly easier and cheaper to build in the "empty areas", and developers would love to build there, were the demand present.
It's not the developers or politicians you need to convince. It's the status-oriented urbanite bugman.
It's the urbanite bugmen who think people in flyover country are all filthy rednecks, who are literally afraid of living in an area without human feces and used heroin needles on the sidewalk, that you need to convince.
These people prefer living in high-cost, high-crime environments because shopping at a bodega makes you the right class of people, not like those trashy Wal-Mart customers. So instead of even considering moving to the empty areas, they bitch about "developers" and "politicians" standing the way of building more $3000/mo 300 ft^2 bugman pods, just so they can tell all their friends that they live in the "right" place. It's all about status, and nothing is sweeter than the tears of these people. Their unhappiness at their self-inflicted "problem" is a beautiful thing.
Status-oriented people are the lowest form of life. Let them wallow in it.
They like being near other people, having access to the services, don't want to waste precious hours commuting, and that's where the jobs are.