Not explicity racist, no.

The timing of these developments was crucial. During the 1960s and ‘70s, in response to fair housing laws and postwar economic gains by people of color, racially and economically exclusive neighborhoods throughout Los Angeles County began to integrate. Not so in the horse-raising zones. It wasn’t that the horse activists were explicitly racist—they weren’t—but that the new zoning dramatically increased property values and thereby made horse-keeping lots inaccessible to most people of color, who had been blocked from accruing significant home equity and credit by the discriminatory laws just repealed.

In Shadow Hills, for example, just one year after implementation of the zone in 1963, new homeowners paid $5,000 more for their properties than they would have paid elsewhere for comparably sized lots—this at a time when suburban properties in Los Angeles County cost between $25,000 and $30,000 on average. The city’s indefinite protection of the “rural atmosphere,” rooted in horse-keeping, is what made the difference, fusing together the historic relationships between whiteness and semi-rural land-use for another generation. Indeed, during the 1970s, the white population of Shadow Hills actually increased, even while other parts of the county were integrating.

I've come to realize there are many things that are not explicitly racist.

Changing the underlying attitudes is going to take society a while.