There's a fine line between "competing to the end" and "delaying the inevitable".
I think part of the problem is sometimes the QB kind of shuffles around for a bit, trying to kill a few more seconds. This only leads to shoving and cheap shots. I've maintained for some time that the kneel down rule should be enforced similarly to the spike to kill the clock - if you're going to do it, you have to do it as soon as you take the snap. That would clean it up a lot.
I think part of the problem is sometimes the QB kind of shuffles around for a bit, trying to kill a few more seconds. This only leads to shoving and cheap shots. I've maintained for some time that the kneel down rule should be enforced similarly to the spike to kill the clock - if you're going to do it, you have to do it as soon as you take the snap. That would clean it up a lot.