Good point, but have you written this up in Moodle Tracker? I wouldn't suggest this is a trivial change, but I don't think it would require a huge rewrite.... maybe.
@Peter, "Most instructors use discussions ... and want the easiest and quickest way to do this, ... ." Yes, agreed, but I suspect that for Teachers it is all about time, the less time they have to spend on something gives them more time to spend elsewhere.