I agree that the person who you originally replied to is wrong (see my comment below) but you’re putting forth a bad argument. It is true that reasoning about and performing an action are different. However, this isn’t relevant to whether bringing up the fallacy in this context is valid. To the point: we are currently talking about and (ostensibly) reasoning whether a specific course of action is good or not. I think that it’s good to vote for Biden. I am overwhelmingly likely to vote for Biden. However, if I voted for Biden because I thought Trump was an actual robot, and therefore unnatural, and therefore bad I’d be committing the appeal to nature fallacy. Now, it just so happens that my counter-factual self would have stumbled upon the correct conclusion, but the fallacy would have been committed nonetheless.
My point was more about the fact that voting in our FPTP system, mathematically, is an act not subject to the same “black & white” fallacy label as a discussion about who is the best candidate, because it actually is a choice between the top two candidates, which is why splitting the vote has been an enduring strategy.
But your illustration about the Fallacy fallacy—that is to say that even if something were a fallacy, that doesn’t in itself mean it is untrue—is also a fair point.
