I'd observe in turn that you seem to have identified very closely with Snape's suffering,
It happens I don't. I've never been 'friendzoned,' never hidden my courtship attempts behind friendship, and never lost a friend due to what seemed to me to be a single event. I have little sympathy for young Snape.
Teenagers aren't well-equipped to build lasting bonds and relationships. Their poorly-controlled emotional outbursts and social anxieties are more likely to lead to defensively cutting contact than building bridges. They break apart easily enough on their own, even if they are, for a time, inclined to each other's company.
Without regard to the degree of the hurt -- and teenagers do react in an exaggerated fashion to minor injuries of ego, don't they? -- people do get in arguments where they never mention the thing that upset them enough to get in an argument. I think that is what the author means us to understand took place between Snape and Lily.
EDIT: New discussion thread here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With two chapters recently the previous thread has very quickly reached 500 comments. The latest chapter as of 17th March 2012 is Ch. 79.
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: one, two, three, four, five, six, seven, eight, nine, ten.
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: