I'm not sure about that. But it's certainly not very compelling logic that he's employing. To continue the unicorn example: If I say that there are no unicorns, am I making a value judgment? Of course not. It's just a proposition which has truth-value. Either it's a fact or it's not.
This guy, dittotl, has quoted some statements by Vichy, and none of them contain any prescriptive language, or subjective evaluation. She makes some statements which are either true or false. And dittotl, in the manner of Stefan, tries to "implode" her argument by claiming that it's self-refuting, which it isn't.