Big fat zero
Any book of netiquette should include, "If you’re going to give feedback, make it useful." In most settings, there’s no enforcement mechanism to make people give useful feedback–nor should there be. In the end, the target of your critique will take you as seriously as you take the critique itself.
That’s my feedback to the person who rated "Product Managers Are Working On The Wrong Things" a zero, with no comments explaining the rating. You expended a few ergs entering the rating, but you should have spent a few more typing comments. If a particular piece of research is truly worthless, please tell us why, so that we can make informed decisions about future research. Otherwise, I have no idea what to do with the rating, other than to scoop it up and drop it in the plastic bag of long-term memory.
FYI, my daughter has an encyclopedic reference of the dumb things I’ve said over the years. (Topping the list is the application of Godwin’s Law to myself: "So now I’m Hitler!" Never mind why I said something as stupid as that.) Nothing you add to that list will be any worse than what’s already there.