Actually, look at the sport as it really is - a group of men tackling each other (contact) while chasing a ball around a 100 yard field of play in order to win. There is as many reasons to put down your opponent than there is strategies to win.
The sport itself is just a combination of wrestling, soccer and strategy and if one is to consider the safety of the players, then it should be considered that changing the game to something else is in order to limit the damage done to these players.
This simply comes down to two things - one is that it can't be played without the contact needed to use offensive and defensive strategies to win, albeit sometimes brutal contact is made only in order to play those strategies ... and the second is that the sport makes money because of the brutality.