Because it separates the Winners from the Losers, the Heartless from the Heartfilled. Competition also makes you have to use all your abilities, and pushes you to limits that you have not yet gone. Without competition, how is one able to find his true value and worth, his strengths and/or weaknesses. Without competiton, how are you to suppose to continually become the best that you can be. Without competition or the drive to be competitive, your simply choosing to accept mediocrity. Is that what you want to be, Identity, Mediocre.