Why do people post 'me too' or 'disagree'? They want their voice to be heard. Specifically, they want to voice their opinion that they agree or disagree with a comment. For most cases, this is pointless. It doesn't contribute to a conversation, it doesn't provide any context, and often it's more emotionally driven than anything else. But I get that you want to reduce the noise of unnecessary comments.
Instead of confusing what a vote means to a user, why not provide meta-votes that reduce noise while allowing users to voice their opinions? Provide a series of buttons with default responses, and allow the comment box to be the 'Other:'. Record these responses and provide a tiny graphic next to a comment that indicates some value based on the accumulated opinions of users.
What this would give you is the ability to change sorting based on emotional and/or intellectual feedback. If you have a sub-thread that has 200+ intellectual feedback, you could float it up to the top of the stack, and keep emotional feedback as a lower priority. People would be able to express themselves clearly and you could disagree with someone morally while ceding that they may have a valid argument. But this is probably a crazy idea, so feel free to downvote me ;)
Instead of confusing what a vote means to a user, why not provide meta-votes that reduce noise while allowing users to voice their opinions? Provide a series of buttons with default responses, and allow the comment box to be the 'Other:'. Record these responses and provide a tiny graphic next to a comment that indicates some value based on the accumulated opinions of users.
What this would give you is the ability to change sorting based on emotional and/or intellectual feedback. If you have a sub-thread that has 200+ intellectual feedback, you could float it up to the top of the stack, and keep emotional feedback as a lower priority. People would be able to express themselves clearly and you could disagree with someone morally while ceding that they may have a valid argument. But this is probably a crazy idea, so feel free to downvote me ;)