I kind of agree with you but I am not sure of the principle at play here. Because I wonder how that would apply if we gave equal status to all outputs of human labor. For e.g. You need to spend money to buy a macbook, so why link to a review? Or you need to buy a book to read it, so why should comments be able to link to a book? etc etc. OTOH we could simply downvote and move on? :)