Downvotes could be made precious by limiting the number one could make each day, ensuring that people will use them more carefully.
It could then be conceivable to give the downvotes more weight, perhaps putting users in a karma hole, with their posts starting out at 0 points, appearing at the bottom of the comments page, if they have accrued too many downvotes. They would then have to dig themselves out by posting more valuable comments.
It could then be conceivable to give the downvotes more weight, perhaps putting users in a karma hole, with their posts starting out at 0 points, appearing at the bottom of the comments page, if they have accrued too many downvotes. They would then have to dig themselves out by posting more valuable comments.