I agree with this -- sometimes the comments are more interesting and informative than the answer. And why is it ordained that "Comments aren't for extended discussion"?

Only a handful of upvoted comments are shown by default, you have to deliberately expand the list to see more, so why not retain them all? If someone wants to wade through 200 commments and add one of his own, what's the real harm? They could add an option for askers/answerers to "Stop notifications for new comments', if that's the issue.