I worked in a few kitchens for a few years. I regularly read reviews on yelp and I would say that near half of the negative "reviews" that showed up on there that pertained to what I myself witnessed or pertained to the kitchen were mostly to totally unfair. The one's that were fair I owned. One of my favorites: one star review for not being seated without a reservation on mother's day. Another favorite review: "I've been a regular here for quite a while and love this place but my porridge was too cold this one time: one star." Another gem: "Food is A+, waiter only refilled our water once: one star." (Pretty much any negative review that centers on waiters can be disregarded; they don't want to eat, they want to be served). I also witnessed outright lies by apparently angry and, I assume, tortured miserable people who were looking to be displeased in every realm of their life. You find those kinds of people in fine dining a lot, rich entitled pensioner types with no respect whatsoever. Unless there's a major sanitation or corruption issue on yelp reviews I take them about as seriously as youtube comments.
Yeah, what's fascinating is that some non-trivial percentage of your customers are going to be unhappy. Pretending it won't happen is silly. You're just insuring you don't have a strategy for when they are displeased. Some complain to your face, and in a perfect world you can do something to remedy that. Others behind your back, which is worse and unsolvable. Porridge should be not "too warm" nor "too cold" but "just right" Great, where have we heard that before.