I'm starting to see that from a seller point of view, if a buyer is not happy with the product its self, they give negative feedbacks. This is bad for the seller.
On the other hand, if a buyer is not happy with a seller and gives a negative feedback, 90%+ will retaliate and give the buyer a negative feedback as well.
There is no advantage to the buyer until now, however in the questions in the feedback, the buyer should separately be able to say what they thought about the item, (if negative) in a way that does not go completely against, (as a negative feedback) to the seller, but still be able to be read in the feedback if another buyer is looking for info on a product.
For example, a positive feedback on a used item but states that the item was a little more used than expected or stated. No retaliation necessary, but it gives both the next buyer and seller something to think about.