Isn't it obvious? You have whales and RMT folks who are heavily invested into the game. You have shill and fake reviews, Lord British fanboys, and don't forget the developers begged on their forums for people to leave positive reviews on steam. It can't go negative because not enough people are even trying it and writing reviews to lower the artificially inflated score on part of the player base and developers. Right now there are only 34 reviews in the last 30 days. However now that it is F2P on steam, anyone who happens to try the game now from the new publicity can leave a review and it will count towards the overall rating, so expect it to only go down from here.