Just look at these blocks. Three de-cleaters in one play! All legal(ish)!
Above is a punt return by Linfield College, and it's about as exciting as any Div III play is going to be. Jump cuts and spin moves don't look quite right when kids try them on at less than SEC speed, but the gigantic, obliterating hit translates to any language, any level. If you want to blink past football's issues and accept it as as an immutable, largely unchanging part of the universe that can be enjoyed in that framework, this is a perfectly fine play to take in. Bow out here.
But if you go through the comments on for this video, on Sports Radio KJR in this case, or for any similar plays on Deadspin or anywhere else around the internet, you'll notice a weird thing happens when you start discussing the individual merit of a big hit. No one discusses whether or not these hits are debilitating. (Of course they are—most everyone agrees on at least that by now.) Instead, the standard procedure is to whip out the rule book and apply as much jargon as possible to the application of the rules, which are themselves likely written with a limited understanding of their practical effect on the game. You saw this with the hit on Le'Veon Bell, with fans arguing over the legality of the hit as the player laid motionless in the end zone, or the fussing over the (il)legal(??) hit that turned Drew Brees into a sea turtle. You especially see it when there is a violent hit that is illegal, like Brandon Meriweather's hits in the Bears game, typically with Mike Pereira on hand to break down the legalistic qualms from the "official" point of view, essentially slapping a uniform on the crossing guard. There is an entire cottage industry involving putting rule-abiding violence in context.
This is the NFL's mind-control apparatus at work. Everyone knows enough to laugh at Roger Goodell trying to sell the league as a safe and reformed place thanks to headhunting and helmet-to-helmet rules. That only makes it more notable, though, that the conversation drifts so immediately to the legality of a hit, rather than its severity or necessity.
This defensive reflex—Well what do you want him to do???—is a brief little peek into the contradiction a lot of rational fans find (probably subconsciously in most cases) in the game as it is now defended. Football is inherently unavoidably violent, the team sport most fueled by ungoverned physical dominance. And the conversation surrounding brain injuries has been, at its most prosecutorial, about the NFL and NCAA doing a a bad, likely negligent job of informing players of the risks and acting in a responsible way to ensure player safety. On both counts, football is much improved, if far from perfect, over where it was 10 years ago. And yet, look at these guys. Three Division III college kids are unable to get up by the end of that play. They know the risks when they get on the field—defend yourself at all times applies well beyond boxing—and the hits they took were legal by every definition that we have right now. It's really hard to legislate chaos bending toward violence, and probably foolish to spend much time trying. And yet once you've stopped and given some thought to brain injuries, it's hard not to recoil from those hits, even if you know the players are properly informed and cared for. That's got to be the driving force behind slapping the rulebook down and defending a play that somewhere deep down makes you uncomfortable: it's one more layer of separation from your enjoyment of the spectacle and the reality of the hit.
In the end, though, this is a small nit to pick. When we've all decided to keep watching football, what does it matter how we decide to make ourselves feel better about it?