Though I agree that the public goes/is insane, I think the real issue is twofold. First, most commercial US airports servicing larger cities were built on open sites in the bi-plane era. Take a look at some 1930s pictures. Open land all around where the predecessor field locations (mostly AAF sites) were chosen. Hundreds of fast jet flights with hundreds of people on board each was never a thought back then. Second, the character of the traveling public has changed from business/well-to-do (say up through the 60s) to everyone now. People now want cheap seats, and really don't care about a two hour+ drive to get to an airport that will save them $100 in airfare.
Good luck trying to add a runway in the northeast - at some locations that would require a really really really big aircraft carrier. Denver and Dallas/Ft. Worth recognized the dilemma and placed their next sites well outside of city limits where coincidentally there was a lot of open space. Bet you in another 50 years, not much open space around either. Even so, it took decades (and finally a threat from the gov't that it would pick the site) for Dallas and Ft. Worth to agree to a location. And do you remember the reaction to closing Stapleton? People were praying for that baggage system to continue to eat bags. Flew in to Stapleton on a Monday and was supposed to fly out of DIA on Thursday. Stapleton was a ghost town - not even a news cart or a shoe-shine location let alone food. All back on Thursday when I again left out of Stapleton - news cart guy told me that was their third move to DIA and back again.
Used to take me 15 minutes to hop in the car and start pre-flight. Then the N-S runway was closed, land sold, office park added. Then they built a middle school less than half a mile from the remaining threshold. One overshoot with fatalities (hit by on-coming car as ac exited runway onto a street) and bam - airport closed for good due to threat to school.