I do think people regularly criticize zoning policy like that in SF as racist, though. A quick Google search seems to yield many criticisms, actually.
If you present a question as a falsifiable test to whether people are consistent in calling out discrimination, I would hope you would be open to changing your mind on the issue rather than simply convince yourself there is instead a conspiracy when new evidence is presented...
It only shows that some people like to call other people whom they don't agree with, with slurs like racist, xenophobe,..., to imply there can't be any other rational explanation other that those people are bad.
If you present a question as a falsifiable test to whether people are consistent in calling out discrimination, I would hope you would be open to changing your mind on the issue rather than simply convince yourself there is instead a conspiracy when new evidence is presented...