There's a sort of short-circuit in the Morton quote between "the concept of nature, and the nature/culture split, is used in certain racist constructions to consign a class of humans to a sort of interzone between the fully natural and the fully social" and "therefore the concept of nature is itself racist". Well, no: there are different possible constructions of nature, the natural and so on, and they're used in different ways in different contexts to do different things. In philosophy I hold to a methodological naturalism which holds that all attributes of the human derive from our being in nature in the last instance: there is no added "special something" that has descended from the heavens and infused us with a divine spark of whatever, it's all scaffolded up through evolution. But I might also talk about wanting to go out and spend some time around a bit of nature, by which I primarily mean the sort of flora and fauna you don't see so much of in a built environment. Unlike certain people I don't see the latter as the Mansion of Authenticity - or Satan's Church, for that matter.