After the Azkaban sequence, Quirrell mentions Avada Kedavra as a technique that can't be blocked and must be dodged, and therefore essential to magical duels. So that's half your answer. If spamming AK isn't the dominant strategy, it follows that there must be other considerations: perhaps it takes more time to execute, or drains more magical power.
In canon I believe it requires actual hatred for the target, not mere killing intent, which would limit its usefulness for people who aren't YA-lit Nazi pastiches, but I'm not sure if we can consider that reliable in MoR. It doesn't seem to fit comfortably into the fic's themes.
In canon I believe it requires actual hatred for the target
In HPMoR too: Chapter 25: "Who'd been silly enough to build in a spell for Avada Kedavra that could only be cast using hatred?"
It doesn't seem to fit comfortably into the fic's themes.
Perhaps update your model on what the fic's themes are?
If anything, HPMoR makes a person's mind-state even more significant than in canon. It buffs up the Patronus charm, it affects pretty much anything having to do with Dementors (how they look like, whether you can hear them, how much they affect yo...
The new discussion thread (part 15) is here.
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 82. The previous thread passed 1000 comments as of the time of this writing, and so has long passed 500. Comment in the 13th thread until you read chapter 82.
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.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
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: