To use an example I gave elsewhere. I order a cable from Amazon. It works. Therefore it met my expectations of a working cable. Yet, I think most people would interpret a 3-star rating as my being lukewarm on my purchase. I'm not. But what the heck do I expect a cable to do other than being a fair price and to work?

With respect to movies. Some movies get really built up and I go in expecting great things (e.g. Fury Road). I come out thinking they were just OK. So maybe 3 stars. But definitely not -1 or 2 stars. My personal expectations aren't necessarily a good baseline.

The way I generally rate things falls in line with this idea:

5: Excellent

4: Pretty Good

3: Average; Unsurprising. Not Impressed, Not Disappointed

2: Kinda Sucks

1: Run Away

This definitely doesn't seem to be how everyone else is using the 5-star scale.