I fear that this is going to have the effect of drowning out minority or contrary opinions, even those that are legitimate (non-trolling) and expressed in a respectful manner. Currently, the downvote button is only supposed to be used for unproductive comments - drivel, and the like. Of course, people use it to show their disagreement (even though that's not how it's meant to be used). As a result, people that post c…
pg has previously stated that it's perfectly acceptable to use the downvote button as "I disagree".