I respectfully disagree that the majority of people accept losing as easily as winning as long as they have tried their best (please correct me if I have misunderstood your point). I for sure don't and the majority of people I have played sports with are exactly the same. I have never been a pro but have played college level volleyball as well as semi-pro level soccer for many years so I have a pretty large database for reference... Same goes for pretty much every tennis match or tournament I have played in (again, non-pro level)
The vast majority of people who play organized sports would take winning with a sub-par effort over losing after they have given it all. Guaranteed.
If you want to argue that philosophically it shouldn't matter then you may have a point. But sportspeople are seldom philosophical about the outcome of the games... polite and scripted interviews by the stars notwithstanding.