[Tiktaalik]

It's absolutely the latter thing.

The thing that is prized above all else is privacy and exclusivity. People are paying money to ensure that few people live near them and that those people are the "right sort of people."

Dating back to the 1930s the original core goal of zoning was to restrict apartments so as to keep poor people and minorities out of certain areas. We know this because it's well documented in the newspapers of the day because back then people were more comfortable explicitly saying how classist and racist they were.