I don’t know what football you played if at all, but the point is to block, tackle, run and score more points than the other team, not intentionally hurt other players.
Yes, players get hurt, but it’s not the goal of the game to knock each other out.
Intentionally hurting another player with an incentive to do so from the coaching staff should be faced with severe penalty from the NFL as it is not what football is about.
Forget about penalties from the NFL. Any player that does this should be arrested by the police and charged with assault.
In the 70's, there was a string of arrests for assault in the NHL:
On-ice incidents resulting in charges
The in-game violence hasn't been completely eliminated, but people no longer joke about going to a fight and seeing a hockey game break out.