I'm not sure that's the same argument. If a chemical engineer wants to explain why she won't research chemical weapon agents, she's not going to say "chemical weapons don't exist" or "everything's made of chemicals so chemical weapons aren't a coherent category". She'll say chemical weapons are a clear, coherent, and real idea, but the risks of understanding them better outweigh any potential benefits.

It's a reasonable argument, and one I personally tend to lean towards, but you can't meaningfully debate it if you don't have a shared understanding that a general factor does indeed exist.