> You do have a point, of course, but in fact the problem often is that people with a bazillion dollars lobby and coerce politicians to change laws and zoning regulations, so that they could make another bazillion dollars.
It may not even be the rich who oppose denser development. Here in Arlington, VA, we have a heavy rail system (DC Metro) that runs through two corridors of the county. Housing close the Metro is expensive because of the convenience.
Prior to the arrival of the Metro, Arlington allowed a section of the county called Rosslyn to get high rises, but it was designed initially in a pedestrian hostile way (it's changing nowadays) and was intended as a dumping ground for the GSA. Ugly 1970s and 60s office buildings with no retail sprung up like weeds.
Meanwhile, the Metro was being planned. Arlington saw the wisdom of transit oriented development and wanted the Metro to be built underground along a major thoroughfare, instead of above ground in the median of an interstate. It fought and won that battle and, at great expense, got the Metro to run along Wilson Boulevard. This, over the course of a few decades, drastically changed this corridor. It's now a walkable urban place with high levels of transit use. In my own zipcode, the majority of people commute to work by means other than driving alone. Many households don't own cars, and even many families might only have a single car.
In planning documents about the areas around the new stations, you can see that ordinary folks were opposed to expanding development too far from the stations or too high. They feared becoming Rosslyn, as documented in some of the planning documents Arlington has put online. As a result, you can walk up and down Wilson Boulevard and see very different land uses:
An example in the Ballston neighborhood:
https://www.google.com/maps/@38.879883,-77.107849,3a,90y,330...
An example in the Clarendon neighborhood:
https://www.google.com/maps/@38.888778,-77.090574,3a,75y,139...
A shot in Rosslyn:
https://www.google.com/maps/@38.896772,-77.072468,3a,75y,178...
As you can see, land use intensity varies greatly despite proximity to the Metro. For added fun, go north or south of these neighborhoods. Notice how within two or so blocks it reverts to single family homes in most places? These could easily be upzoned, sold to developers, and make lots of money for the county and developers. The Metro would love to have additional transit dependent customers as it's going broke. Businesses along Wilson and Clarendon (the main drags) would love extra foot traffic. But they're not zoned for high density. Pure bribery doesn't explain this.
Bribery might explain why it hasn't changed in the modern era though. Modest, 1950s homes sell for over $600,000 or $700,000 regularly depending on the number of bedrooms. $1,000,000 might be a reasonable price if it's got four bedrooms.
Newer construction easily sells for over a million. Depending on the exact location, a one or two bedroom condo will run $400,000 to $500,000. Three or more bedrooms and you're in million dollar territory. We've not yet hit San Francisco prices, but the D.C. area is attempting to get there.