When whoever is abusing this feature figures out what the new low threshold is they'll just use that instead. They ought to just be IP banned and gotten rid of, frankly.
Worth noting: I DO NOT WANT the email address of someone who gives me a minimum rating on a premium item like some of the things I've posted here. We don't have anything to talk about. If you folks aren't interested in curbing this kind of malicious crap then tbh you ought to just turn the ratings system off and use # of downloads for whatever ranking nonsense you feel compelled to track.