I think that just for sending feedback, let alone getting it rated you should get a small amount of FP's because this...
1. Helps you to claim the little decimal points we have in our account such as 0.6's to help make them whole numbers
2. Even if you complete good feedback but they rate your site like one star or two star, you still put the effort in. But if it is obviously a rubbish review, and wins in a dispute then the points will the be automatically deducted.