I have a friend who has four restaurants in Tokyo, and I've been several times there. If you keep attention to the restaurant reviews in Google Maps, Japanese people is very hard. They'd go like "The food is great, incredible service, surprising flavors, very good experience, best Spanish food I've had in a long time..." and then they go "...but I know they can do better and have space to improve. 2/5".
In Spain we would be like "Nice beer, they gave us some tapas. 5/5"
Gig economy corporations also have made this worse. You're scared to score your driver, your server or your hotel by less than a 5/5 or somebody might get punished or fired (and maybe they didn't even had a contract in the first place).
And this becomes a snake biting its own tail. Now I rarely go to a place with a score of less than a 4/5, and I'll score relatively high because I know I could influence votes out of what people consider "worthy to visit".