Many people don't know that judged sports actually have extremely detailed codes for what is expected from each element. For example, gymnastics has a "Code of Points" that details the EXACT specifications of every single gymnastics element on every apparatus. The "judging" is not meant to be a subjective measure of how much a judge likes a move; it's a judgmenet of whether the move was executed correctly according to the Code of Points.
To draw an analogy, the judges in gymnastics are more like the plate umpire calling balls and strikes in a baseball game. Balls and strikes are not called based on whether the umpire likes a pitch--they're called based on whether they're in the strike zone. In the same way, a judge in gymnastics doesn't simply decide what "looks good"--there is actually a very specific set of things that is meant to happen in each element, and the judge enters scores based on whether those elements were executed correctly. The requirements are very specific.
To draw an analogy, the judges in gymnastics are more like the plate umpire calling balls and strikes in a baseball game. Balls and strikes are not called based on whether the umpire likes a pitch--they're called based on whether they're in the strike zone. In the same way, a judge in gymnastics doesn't simply decide what "looks good"--there is actually a very specific set of things that is meant to happen in each element, and the judge enters scores based on whether those elements were executed correctly. The requirements are very specific.