Well, people are less likely to believe in an idea if an argument used in favor of it later turns out to be entirely false. For example, if I say "green jelly beans are slightly carcinogenic" and someone says "yes, also each one you eat has a 1/100 chance of killing you immediately", makes a lot of publicity about this, and months later it turns out that that statement was completely unfounded, then people will be less likely to believe me now. Even though they have very little new information compared to just me saying "green jelly beans are slightly carcinogenic".
So in this case we have people saying "Look, some Slytherins are good, see QQ!", and gaining some amount of support with that. QQ turning out to be Voldemort would not only defeat everything the argument did (which is not bad in and of itself, the argument was after all flawed), but also cause a backlash which would make Slytherin appear worse in comparison to before QQ was the Defense Professor.
Hm. While QQ was widely praised as being a great teacher, I don't think anyone missed the fact that he was radiating a constant aura of evil (before the fact that as the Defense Professor he was guaranteed to be evil by definition). I think his contribution to public perception would have been "some Slytherins are incredibly badass" rather than "some Slytherins are good".
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 116.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)