Three years ago, FT had an article praising Tokyo’s laissez-faire zoning laws. Landowners can build and demolish as they see fit; the rules are set at the national level, so local governments have no say in the matter.

The article suggests that San Francisco could learn a thing or two from relaxed development rules. Ha. Hahahahaha. Why on earth would San Francisco residents want to liberate housing development??

In Japan, a housing development is the developer’s business. In San Francisco, it’s everyone’s business. Neighbors appeal building permits based on traffic considerations, shadow effects, environmental impact, historic preservation, and all manner of other stuff.

Here’s what they really want to preserve:

San Francisco is culturally diverse, but the diversity* is strictly segregated. We call this historical character, and character can only be maintained by keeping outsiders out. Neighborhoods can’t exactly come out and impose cultural segregation, but they can enforce zoning laws. By blocking new buildings and preventing the renovation of old ones, residents ensure that the demographic makeup stays the same year after year.

When policy initiatives aren’t enough, diversity can be preserved in other ways. In Chinatown, landlords often advertise vacancies only in Chinese newspapers and sites, ensuring that incoming residents are also Chinese. The Mission District promotes gentrification resistance movements such as the Yuppie Eradication Project and Causa Justa, which tracks the number of Latino households displaced by white residents.

In any other city, we might start slinging the r-word around. Here in San Francisco, it’s a reasonable fear of displacement. I suspect that most of what we call racism today is this same type of fear.

City residents are right to be scared: The Fillmore District used to be known as the center of West Coast jazz, the Harlem of the West, until it was targeted for redevelopment in the 1960s. Urban renewal destroyed the Fillmore’s low rent housing, forcing tens of thousands of diverse residents out of the neighborhood. The development was widely criticized as a “N…. Removal” project. Today, the Fillmore District is just another place where rich tech workers live.

San Francisco is frequently charged with NIMBYism, in which wealthy landlords are accused of blocking development to uphold property prices. While it’s easy to rip on the landed gentry, low income residents are actually some of the most vocal opponents of new development.

75 percent of San Francisco’s rental stock is under rent control, and many units are priced so far below market rates that no amount of free market development could keep these tenants in their homes. The locals don’t want to compete with newcomers for business and housing because they know they can’t.

It’s these charming pockets of xenophobia that have preserved San Francisco’s historical character and made it such a desirable place to live. If SF were to liberate its zoning regulations, it might turn into San Jose.

Don’t get me wrong; San Jose is a lovely metropolitan area — I practically live there myself. San Jose is an older city with a history that goes back to the 18th century Spanish pueblos, but its historical character has long been displaced by the urban developments that rich hipsters are now trying to shoehorn into San Francisco.

So we can either have a bunch of segregated areas with rich cultural history and strict zoning plans, or a culturally dispossessed Frappuccino. It’s worth noting that, despite offering lower rent and easier access to the likes of Facebook and Google, Silicon Valley tech workers would rather not live in San Jose.

*I realize that the word “diversity” is constantly evolving. Here, I use it in the liberal sense of having representation from racial minorities.