It is really simple: The greater your natural ability the higher expectations for you will be.
Richarlison is by far the most naturally talented footballer at EFC. We as fans expect him to deliver on the promise of his god given ability and when the things that are preventing him from being a world class footballer are completely within his control (i.e. decision making, positive attitude, team play, not throwing himself to the ground every 3 minutes) we as fans are rightly frustrated.
In the case of Richarlison the above issue is exacerbated to a point that many of us want him gone because even if a footballer less talented takes up his position. As a fan supporting a team of players who exemplify morality, work ethic, and team play is more enjoyable because even when you lose you still have respect for the players and they provide a good example for your kids.