The possibility of concussions is present in [nearly?] every sport. Typically, head injuries are not a core part of gameplay. In the case of soccer, there have been concerted efforts to remove "heading" from practice and from games. Football is being targeted because minor/severe concussions are commonplace and result from a core aspect of the game.

> The possibility of concussions is present in [nearly?] every sport

Tennis, golf, swimming, weightlifting, etc - probably have a pretty low incidence of concussion. Stuff with teams and fast movement are probably most suspect; hockey and football would intuitively seem like the worst offenders.