Ask HN: Why Not Upvote Civil Disagreement?

Instead of downvoting all comments that you disagree with, if you upvote the civil disagreements then you will help to curate deeper and more meaningful discussions. Upvotes are a reward for good behaviour - they release dopamine in the brain - and civil disagreement is not bad behaviour.

Of course, this means nothing without an official seal since PG already proclaimed that you should downvote disagreements. But I thought it might be worth a discussion. Are there any downsides to this proposal?