Agreeing is like saying 'Hey dude! I like your opinion!' Thus why it is positive. Negative ratings are neutral because it's like saying 'My opinion is different to yours.'
I really don't know about this. But I liked it the past way. It shows generally if that person comes up with good points of view in different situations.
I don't see the need to make the "Agree" rating neutral. If someone agrees with you, that's a good thing, so it's a positive rating. If someone disagrees with you, that isn't necessarily a bad thing, as said above.
