At different times, there have been a bevy of complaints leveled against. For the purposes of this (relatively brief) post, it's not worth getting into all of those. The two prevalent complaints that are important here are as follows: 1) Davis does not run a variety of formations -- the base offense in most years is 11 personnel with the tight end and two receivers on the strong side of the field, and 2) Davis does not put players in motion before the snap.
Before delving into the possible reasons for those two systematic decisions, it's worth further clarifying the complaints against Davis. As for the first complaint, Mike Leach famously said in the Michael Lewis article that he likes to run the same concepts from different formations to confuse the defense and affect their coverages because it's harder to teach different plays than it is to teach players to stand in different locations -- teaching them where to stand is easy. Leach sees and, quite possibly, has experienced, no problems in lining receivers up all over the field but running the same plays from those new positions, doing so helps disguise the basic concepts he runs over and over.
The second complaint mainly centers around the fact that putting a man in motion helps the quarterback with his pre-snap read by forcing the defense to show either man or zone coverage. If a defender follows the man in motion, it's man coverage, but if a defender does not follow, it's zone coverage. One of the major takeways from this current Texas season is that Colt McCoy is an infinitely better quarterback when he can determine where he wants to go before the snap -- of course, this is also surely the case with virtually any other quarterback as well.
Back, now, to the original point. Chris Brown just posted an extremely interesting article over at Smart Football in which a friend of his ("Hemlock") who coached the run and shoot both at the high school and collegiate level provides some insights into why Davis almost always uses the same alignment and almost entirely eschews motion.
The most probable reason for Davis only using the same basic alignment is simple -- it keeps his own players from becoming confused. Though Leach apparently has few problems with his multiple formations, personal and anecdotal evidence from Hemlock suggests that it isn't as easy as the head pirate suggests:
I've coached both high-school and D-I football and I've learned the hard way that it is either impossible, in the case of high school, or or so difficult to the point of being prohibitive, as in the case of college ball, to effectively implement a multiple-formation intensive system and to consistently succeed with it. At my last D-I school we ran the true west coast offense, as my head coach was a legitimate disciple of Bill Walsh. Not only was it difficult to install all of our formations, but it made our players hesitant; they were so worried about getting lined up correctly that they were not able to concentrate on running the play. Another unintended consequence was that the different looks we installed confused our players more than the defenses we faced. It sounds odd, but our players, despite all our efforts to the contrary, deep down believed that every time we ran a route concept from a new formation we were in fact running a different play. This problem reinforces a point that June Jones made once about his former quarterback Colt Brennan. Even though they ran their "Levels package" primarily from one formation ("Early"), Brennan, for nearly a year, believed that the different level distributions constituted a different individual play. It took a year, according to Jones, until Brennan basically understood that regardless of who was the over and who was under runner that they were running the same play. Now, remember, this was all being run from one formation; imagine what it is like when you have literally a dozen different formations from which to run that one play. We found out the hard way: We had a lot of formations and our players thought we were drawing up all kinds of new plays.
As Hemlock mentions, coaches at the college level have much less time than professional coaches to spend practicing installing plays or watching film with their players. No doubt the level of maturity and brain development (the frontal lobe does not function at peak capacity until the early to mid 20's) also impacts the ability of college-age players to grasp different formations with the same route concept. When combined with the talent advantage that Texas enjoys in nearly every contest and it becomes apparent why Davis prefers keeping his formations simple -- the opposing defense often can't stop the Longhorns even when they know the play that's coming.
Hemlock also provides a possible answer for the second complaint -- not putting players in motion. While the motion man does provide the quarterback with a better pre-snap read on the surface, an original intent of using motion nearly every play in the original run-and-shoot offense pioneered by Mouse Davis, Houston's John Jenkins realized that defenses were catching up:
But, one result of the 'shoot's success was that coverages became more advanced in response. Jenkins stayed ahead of the curve and saw it happening before it actually did. He understood that that motion could actually lead to false keys that would hamper his offense's ability to execute. Consequently, Jenkins began to use leverage as a way of decoding a defense's intentions. Another reason he abandoned motion was that he understood that it could lead to sloppy route running. A big key to the run and shoot is to "stem" your route correctly - i.e. begin off the line in a particular direction to set up the routes. Motion can be a lazy man's way of dealing with press coverage. Great technique though is better and will result in a better stem, which lead to a better route. One other point in regards to this is that stemming your route means identifying who in the coverage structure you are running your route off of. Again, motion can muddy the waters.
Without the key advantage of putting a man in motion, what's the point?
Texas fans have often complained in the past about the Longhorns running the same play over and over again -- it works great, they say, against overmatched defenses, but what happens against teams with equal or greater talent level? As the Cotton Bowl match ups against Oklahoma in the early part of the decade clearly demonstrates, the results ending up being poor.
However, repetitions are extremely important at the collegiate level. With limited practice time, focusing on several key plays and concepts to make sure that each player executes his assignment well is much more important than having a complex playbook similar to those used in the NFL. Coaches jumping from the NFL to college who have experienced recent struggles include Bill Callahan, Charlie Weis, and Mike Sherman, all of whom had to simplifty their schemes in college. Well, perhaps Callahan never did, but that goes a long ways towards explaining why he was such a complete and abject failure at Nebraska.
Relatedly, Hemlock levies the complaint against Florida State head-coach-in-waiting Jimbo Fisher that his offenses don't do anything particularly well, citing that his concepts do not blend together to create a systematic whole. It's also possible that Fisher tries to be too many things at once -- instead of doing several things well, he tries to do many things well. Since I haven't watched enough of LSU or Florida State to know if that is true, I'm simply making a supposition here that supports my next point. For Texas, it's always been much more important to do several things well, like run option routes with inside receivers, the iso play with Ricky Williams, or the zone read with Vince Young, than it is to try to incorporate many disparate elements into the offense. Once again, execution reigns supreme.
After all, would Marquise Goodwin be able to contribute this season if he always lined up in a different spot on the field? A remarkably mature and quick-learning young man, it might be possible, but if the experiences of Hemlock serve as a guide, then perhaps not. The crucial late interception against Oklahoma that could have been returned for a touchdown without McCoy's saving tackle was a result of Goodwin running his slant route behind the receiver, something he should never under any circumstances do. Would motion help McCoy more often make the correct pre-snap read? Perhaps not. The struggles of the Texas offensive line this season also illustrate just how important it is that every player execute their assignment and receivers being out of position, especially on "trust' throws, where the quarterback expects a player to be in a certain place, results in a high probability of the quarterback turning the ball over.
So while the Smart Football post mainly discusses these issues within the context of a run-and-shoot offense, the problems are universal and provide excellent explanations for why the Texas offense does not make use of multiple formations or put players in motion -- for Davis, on the college level if just makes more sense to run things the way he does. And, for once, it's hard to criticize Davis for that.