Which is the bigger threat: Nominalism or Realism? Peirce’s visceral reaction highlights how deeply realism is tied to meaning-making for some, without universals, the world can seem empty or arbitrary. But from the nominalist camp, that same insistence on universals can look like projection or even imperialism of the mind over experience.
Critics of nominalism like Dugin and Benoist do often connect it to the unraveling of traditional identities, but as you point out, that assumes the legitimacy of those categories in the first place. From a nominalist view, those identities are constructed and contingent, not essential truths. So if realism can support oppressive structures by making them seem eternal or “natural,” then yes, it has its own dangers.
For a strong case against realism, Richard Rorty comes to mind, he didn’t see truth as correspondence to universals but as what works in conversation. His pragmatism was deeply nominalist. You might also check out Nelson Goodman, especially in Ways of Worldmaking, where he questions whether there even is a singular “world” apart from the symbols we use to carve it up