Phoenix utility functions are not human-friendly; they do time discounting differently from us. It's not that rationality is hard, but that true rationality combined with human values like Harry's does not meet with phoenix approval.
The post-edit Harry decided he would do the phoenix-right thing later. Once he decided that, the phoenix went away, and will not return. If he had decided that firmly earlier, presumably the phoenix would not have come to him in the first place.
The pre-edit Harry struggled with a similar question. To be consistent, I agree that a phoenix could and should have come to him while he was struggling. But once he had made his decision, the phoenix would definitely not come. Those are the phoenix rules, as given by the update to this chapter.
The decision Harry had come to pre-update was that he would not do whatever it took to free the prisoners of Azkaban; and also that he would not do whatever it took to protect his friends and strike down evil, until he allowed another person to die through being ineffective. Those are not decisions a phoenix would approve of. (Which is not to say I don't approve of them.)
What are phoenixes trying to accomplish?
Edit: New thread posted 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 86. The previous thread has long 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.
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: