Basic human nature is good, but "civilized" human nature is a balance on a knife-edge, between "civilized" survival (which ultimately requires ethical thought and practice) and corruption. Sportsmanship is great but sport in itself (as with religion) shows how easily corruption can take hold, fouling-up whatever is genuinely creative and wholesome.
What changed the path of social evolution for Syai civilization was the profound understanding that the cleverness of the brain can be used to enhance the benignity of civilization (from most individuals' point of view) and the beauty and sustainability of the natural environment. But on the other hand the cleverness of the brain can alternatively be used to enhance environmental over-exploitation, and the advantages of individuals and 'in-groups' over non-connected individuals and 'out-groups'. Unlike my imagined Syai world (and other possible worlds out there that may have awakened to the potentialities of long-term survival of intelligent beings) our world is at a turning point! A dark uncertainty hangs over it. Economics, religion and (professional) sport are three societal areas in which the Syai civilization would strike many people on this planet as very revolutionary; but not totally out of reach. Syai sport, for instance, has great regulatory importance in both fostering general happiness and preventing all kinds of malfunctions and self-seeking temptations, but there is no such thing as professional sports players or teams.