It's not that people here don't make mistakes, but that mistakes are dealt with reasonably. If someone abuses their power, they're terminated and possibly banned depending on the situation. Getting through the selection process to be a GM is hard, and requires a lot of time and work helping players. This isn't a matter of perfection, but how a server is run and the features it has for the players. I can't agree with your "balancing theory" because it only takes one bad review comment to make a server look bad. There's a difference between "not liking" a server, and having a personal grudge to where you would spam bad reviews. I can't agree with the your balancing theory because people can read the player typed comments and not just look at a pure number rating.
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I hope server owners will have the ability to report with their owner accounts soon so I don't have to make another account just to use the report button.