Of course there is a difference between doing your job and trying to hurt someone, but they kind of go hand in hand in contact sports. It's contradictory to say, "go as hard as you and hit him as hard as you can but don't try to hurt him."
That doesn't work in real life, it sounds good theoretically, but it's impossible to do that in a game that is as fast as football where 22 guys are flying all over the field trying to level each other.
You're in denial if you think these guys actually care more about each other than themselves.
I really don't think you see the point.
There's a difference of hitting someone as hard as you can and hitting someone as hard as you can with the intention of hurting them. Injuries naturally happen, same with the occasional helmet to helmet shot, but if you have the intent of hurting someone, it's different. If you get PAID to hurt someone, that's even worse. When it's a collaborative effort to hurt a guy by hitting him after he throws the ball, jumping on the pile, running into him on the ground when there's a fumble, that's the problem. They may not be against the rules, but if you don't see the difference, you're blind. When normal players hurt someone in the play, it's natural. These people are conspiring against players and getting paid for it.
This isn't a pick one or the other scenario, guy. IT's not like "I can't try as hard as I can if I want to injure him" or "I don't care about myself more if I'm not trying to hurt them."