There is, I believe, a commonly held but largely subconscious concept that sportsmanship resides in a liminal space between civilization (the outside world) and barbarism (the playing field). For almost all sports, this is a no-brainer: you play hard, you play to win the game, but afterwards you shake the hand of the man on the other team and act within the civil bounds society has laid out. That's good sportsmanship; that's class. We applaud guys that "play the game the right way", and we vilify those that don't, even if they are exceptionally talented and at the top of their field. Richard Sherman is one of those villains, and most people hate him for it. A small minority love him for it.