... of using comments as added points for a story.
While a good number of comments are actually discussion generators in one way or another, there are a few which are simply criticisms of the story. As for the one presently under debate, #15, #16, and #19 strike me as being such comments. Such comments would tend to flaw a system of blindly giving a +0.5 score for every comment posted.
There's also the fact, that others have already gone into, as for the opportunity for abuse. Arguably, you can work around this by limiting the amount of posts a user can make to a story before it hits the main page, but that strikes me as anti-discussion, and rather against one of the major points of kuro5hin.
Third, if you use this system, there's going to come a time when, with all the added comments points involved, there's still a story that comes very close to making it to the main page, but not quite. Then it's back to the drawing board again.
Frankly, I would simply have the admin(s) give the story and comments a good re-read, considering all points for and against it (and yes, controversy may be such a point on either side), and make a final decision for themselves. I think that, overall, this solution allows the most room for flexibility on such heated stories, and does not create a new, complicated system which could very well land us in the same situation at some further date. Yes, it arguably takes away a bit of power from the users, but with such hot topics, I don't believe that you will ever find a system that accurately judges a close to 50-50 split among users. Eventually, an appeal to authority will have to be made.