Facebook has the need to not put a dislike button, because if they do, people will not be compelled to write a comment feedback perpetuating the display of ads, they will be done with just a dislike. If they implement a downvote/dislike button, any negative post can have the like/dislike ratio it deserves and people will not click it, generating less revenue for facebook. As it is currently, any stupid post will still get a bunch of likes anyway. People are the product being sold, not the customer. Don't expect a dislike button that can hurt the feelings of the poster (or that's their excuse). Expect more of the same stuff we have seen always.