Frankly, even though the origin of the question might be a bit of a joke, it's actually pretty logical. I think it's not that low review scores are better in any way, but numerous five-star reviews don't say much about a story. They're unreliable, so to speak.
Some people casually give five stars to stories they just liked, while another person will give five stars only to an absolute masterpiece. There is a similar discrepancy at four stars and any other rating, but it's not nearly that glaring, and so it makes reviews around 3-4.5 stars much more reliable when you want a serious answer how good the story actually is.
One-star reviews though have the same exact problem as five stars.