This week Valve have changed the way reviews on Steam are shown. They say the previous system wasn’t really working because the reviews are not indicative of the current experience. An example of this would be a game being really bad during early access and excellent a year after release. If the early access reviews outnumber the average reviews will always be negative, regardless of the current game being excellent. A more common case would be when developers of a highly thought of game with an active community do something the community does not like causing a backlash in the form of negative reviews. Here is Valve’s post about the changes.