Well, I can't answer for Eliezer's intentions, but I can repeat something he has often said about HPMoR: the only statements in HPMoR he is guaranteed to endorse with a straight face and high probability are those made about science/rationality, preferably in an expo-speak section, or those made by Godric Gryffindor, his author-avatar. Harry, Dumbledore, Hermione, and Quirrell are fictional characters: you are not necessarily meant to emulate them, though of course you can if you independently arrive to the conclusion that doing so is a Good Idea.

Is this really supposed to be one of the HPMOR passages which is solely about the fictional character and is not meant to have any application to the real world except as an example of something not to do?

I personally think it is one of the passages in which the unavoidable conceits of literature (ie: that the protagonist's actions actually matter on a local-world-historical scale) overcome the standard operation of real life. Eliezer might have a totally different view, but of course, he keeps info about HPMoR close to his chest for maximum Fun.