Competition is everywhere in school. Announcing grades (regardless of whether they're anonymous), grading "on a curve", spelling bees, sports teams, all these things involve competition. Even team sports, where teamwork should be taught, those who do better are rewarded.
This teaches kids that everyone else is there to be beaten. Only help when it helps you even more. Also, they don't want to be seen as the Loser. They may try to be the winner at all costs, even if it means cheating.
This isn't good. Teamwork needs to be encouraged. Grades should all be Pass/no pass. Learning how to work in a group and socialize in a friendly manner should be emphasized.