I think people defend anti discrimination or are against it depending on how the anti discrimination policy discriminates discrimination.
We always discriminate. We have to. But only some discrimination is allowed and some are not allowed. The difference is what kind of discrimination people feel is fair and unfair.
I agree that humans discriminate inherently, although I would argue that what differentiates us is whether we struggle against that impulse.
On some level, the idea that we all discriminate has the potential to help us move beyond the "racist/not-racist" dichotomy. (I prefer the formulation "we all discriminate" over the dubious alternative "we're all racist".) But I'm not sure it will ever achieve mass acceptance, because it activates the human impulse to self-justify.
I dream that one day someone will come up with version of this idea that is universally acceptable.
We always discriminate. We have to. But only some discrimination is allowed and some are not allowed. The difference is what kind of discrimination people feel is fair and unfair.