I think people go to Slate Star Codex, because that's where Scott writes his articles, not because of the voting mechanism.

From the paper:

authors of negatively evaluated content are encouraged to post more, and their future posts are also of lower quality

Seen that at LW a few times. At some moment the user's karma became so low they couldn't post anymore, or perhaps an admin banned them. From my point of view, problem solved.

I think it would be useful to distinguish between systems where the downvoted comments remain visible, and where the downvoted comments are hidden.

I am reading another website, where the downvoted comments remain proudly visible, with the number of downvotes, and yes, it seem to enrage the user to write more and more of the same stuff. My hypothesis is that some people perceive downvotes as rewards (maybe they love to make people angry, or they feel they are on a crusade and the downvotes mean they successfully hurt the enemy), and these people are encouraged by downvoting. Hiding the comment, and removing the ability to comment, now that is a punishment.