[Steffen]

The team winning the flip has some kind of advantage. Usually they choose 1st offense and would therefore win a game in which there are no break points. (The fact that the other team has the offense after half-time is not enough to mitigate this advantage.) If the flip was replaced by another activity, for example a competition of two players of the opposing teams to throw the disc as closely as possible to the opposite brick mark from a goal line, the win in this case would at least be determined by some kind of skill instead of pure luck.