I don't think it's the numbers so much as it is the familiarity. Were I familiar with any one Azkaban inmate, assuming the wizarding justice system is at least decently effective, I'd probably say "Yeah, this guy is probably guilty. Sucks to be him, but he should really avoid killing people next time". That is not what I think when I see Hermione suffering. Even knowing that there's probably several Hermiones in there, not knowing which ones they are makes empathizing with them a lot harder.
assuming the wizarding justice system is at least decently effective
Based on how Hermione's trial went, this probably isn't a safe assumption. Many of the people in Azkaban may have just pissed off the wrong person (e.g. Lucius).
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 88-89. The previous thread has passed 500 comments.
There is now 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.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: