Many TripAdvisor reviews are fake. Some positive ones are paid for by the restaurant, and some negative ones are written by competitors or by people extorting money from the restaurants. Some review sites charge hotels and restaurants money to remove negative reviews and make a significant amount of their income from this.
Google for TripAdvisor and "fake reviews" and you will find lots of news stories saying that up to a third or more of the reviews are fake. The proportions at other review sites are usually similar. Highly rated restaurants and hotels tend to have a higher proportion of fake reviews.
To tell you how easy it is to game, here's a story by someone who "created" a non-existent restaurant and got it to the #1 ranking for London (UK) in TripAdvisor. Before writing articles as a freelancer he used to charge restaurant owners £10 for positive reviews of restaurants he never visited.
I Made My Shed the Top Rated Restaurant On TripAdvisor
I'm not going to claim that the bad meals you had were due to fake reviews. I will say though that you need to take on line reviews with a large grain of salt.