While others sift through the HUNH injury arguments, we can discuss the HUNH as a tactic and strategy in football. According to Danielson, "The hurry-up is a tactic, just like screen passes and traps and pick plays. Everything is a tactic, but the HUNH is given way too much credit. It's just producing more plays." Unless Danielson is just being loose with his words here (and that's unlikely based on the quality of his other comments in this interview), it's interesting that he describes the HUNH as tactic as opposed to a strategy, a trend, or overall football philosophy. To Danielson, then, HUNH is merely a tactic that teams can employ situationally in certain game scenarios. This contrasts remarkably with someone like Gus Malzhan, whose teams -- and really their entire programs -- are in hurry up.
Leach seemed to suggest he thinks of the HUNH as a tactic too, saying that, "We're a little more limited in using the hurry-up than some. I can't say we've ever utilized it as much as some teams do, but we've never not utilized it." In fact, this -- the tactical implementation of HUNH -- is true of all coaches at all levels, and throughout most of college football history. What is the two-minute drill but a situational implementation of the HUNH?
So, the debate here is not over the tactical merits of the HUNH necessarily, but of its strategic utility and its effect on the philosophical roots of the game. Here Danielson critiques Saban:
I do think Nick [Saban, one of the proponents of the 10-second rule] has a point: football was not originally meant to be a continuous sport. But I think it's stupid coming from Nick, and I don't understand why he's doing it. He has the best players! He theoretically should have the most well-rounded players, and he could look more like the Seattle Seahawks than anybody else in college! But he fights it. Just swallow hard and put guys in there who can do a lot of things. You've got the better players.
So, Danielson is saying that Saban might have a point about football philosophically -- football isn't and shouldn't be rugby or any other continuous sport -- but he's wrong to complain about other offenses employing the HUNH. He already has "got the better players," so, suck it up.
However, there are strategic reasons why Saban (and other coaches) does not employ the HUNH on a more than tactical, situational basis. I don't believe that anti-HUNH advocates are motivated entirely by philosophy or injuries. Nor are they only anti-HUNH because their defenses are gashed by lightning-fast snaps from Johnny Manziel -- why then wouldn't Saban's offense run the HUNH?
Instead, Saban has made a strategic choice against the HUNH, and my hunch is that it is due to (1) trade-offs in player size, (2) complexity of schemes, and (3) abilities for pre- and post-snap reads.
To some degree, and I want to emphasize that this is my speculation and I haven't tested this yet, teams likely trade some degree of player size and strength for the conditioning necessary to run plays at break-neck speeds. Athletes that are bigger, stronger, smarter, and faster than their peers aren't exactly a dime a dozen. And if anyone is going to be able to recruit those guys, it's Saban. Simply (and simplistically), strength and conditioning programs have to specialize their programs to a degree to develop their players for the offensive system the team runs. Anti-HUNH coaches might then choose bigger (and maybe stronger) over faster and better conditioned, particularly when it comes to offensive linemen.
Second, as Danielson mentions, "[Hurry-up teams] keep things very simple in their play-calling -- no intricate pass protections -- and very easy to repeat." While this deserves some further analysis, it makes intuitive sense. You often read that some coaches will call the same play five or six times in a row in HUNH if defenses are unable to adjust. Not only does this make sense tactically (run it until they can stop it), it makes sense based on the mental limits of calling plays quickly. My guess is that coaches also use particular decision-making heuristics in HUNH compared to when running plays more slowly, emphasizing the base, most repeated, or most recent. It is far easier for both coaches and players to run the same few plays in a play-calling series in HUNH than it would be to call multiple protections and plays at lightning speed.
Finally, and related, if the goal is simply to snap the ball as quickly as possible, the offense is making the choice to forgo some benefits of pre-snap read times. Of course, very few coaches are so wedded to HUNH that they do not vary their tempo at all. Urban Meyer and Chip Kelly, for instance, are arguably known more for varying their offensive tempo between three speeds than for running break-neck all the time. The idea with snapping the ball as quickly as possible is that it dictates the pace to the defense, forcing them to not substitute and either align in more simple, base coverages, or risk being out of position when the ball is snapped. However, this is obviously a tradeoff, as defenses may adjust and learn to better disguise coverages more quickly against repeated offensive fronts.
So, Saban is making a conscious, strategic choice to be anti-HUNH because there are important tradeoffs. The HUNH might or might not be strategically superior, but there are certainly some benefits slowing things down too, namely in player attributes, scheme complexity, and play choice.