I know how you're trying to use it, I brought up the etymology. Your usage isn't new, I'm just adding rigor. Even "violative of; contrary to" categorically negates the validity of the actor's reasoning. Taking the descriptive position is your option, but I hope we can agree that that would be "literally"-ing the word, given the science.
I’m fundamentally a descriptivist when it comes to language: words mean what people use them to mean, not what they “should” mean based on etymological history. Negating the validity of the actor’s reasoning is generally what people who call things unethical intend to do, and I see no evidence that usage has changed significantly in recent years. As their intentions are clear, I see no benefit in claiming the concept is nonexistent.
In fact, deigning to judge an act as either ethical or unethical is implicitly admitting that the actor has agency and therefore reasoning powers: someone’s reasoning cannot be invalid unless it exists.
