Games are complicated products. One part of a specific game can be really good while other parts of that same game are really bad. So even labeling something “mediocre” is reductive. I haven’t played all the games you are talking about, but for cyberpunk they hyped it up to be far more than it was, and they released a severely buggy product at launch. So people were rightfully pissed. Since then it’s received a lot of patches and now people enjoy the game much more.

So not meeting expectations is a big part of it. If everyone is expecting 9/10 experience and you deliver a 6/10 with a bunch of bugs, they are gonna be more upset than if they were expecting a 6 out of 10 and that’s what they got.