I think it’s because if the thread is large, then someone who is scrolling through it real quick can just pick out what other people think are great answers without having to waste time.
I think they’re still test driving it, though, I had forgotten to mention that, but should have. I think there’s another thread on it, just poke around a bit, it’s not that old.
DeezerQueue is right. If you ask a question and give points to a answer the link will turn orange. This only happens if the person that asks the question clicks on a great answer.
This is so you can know if you actually helped the person.