How ratings will help an author?
Rating will help author cause when a purchaser or client comes up on your portfolio want to purchase something from you that he/she will understand many thing about you or any other author from his profile review.
How about author item support quality, about item quality, item code quality etc if that client/purchase satisfied on your previous item or his chosen item previous review then he/she will purchase your item easily and satisfied on you even he will left a new review for your item.
Even you will be a faithful author for him and next time he will come on your portfolio to purchase new license or another category chosen item.
hope you understand.
let me know any other question.