His main problem is the inability to make adjustments. It is that plain and simple. If all goes according to plan, ie: nobody gets injured/ suspended, he's fine, because all in all, he has assembled enough first line talent to compete in the top ten in the country. He just does not have enough depth, due to various reasons, whether it's because of transfers or that he cannot recruit jucos or get transfers himself. But 2012 is an example of all going right, not suffering any crippling injuries and his team being clutch when it counted.
Another example is how he handles his offense and particularly his quarterbacks. In 2013, he was forced to play Rees. Ok, that sucked and was a tough situation due to Golson's suspension, but he still had a manageable enough schedule and enough talent to win at least 9 if not 10 regular season games. Instead ND won just eight and a major reason was because of Kelly's inability to adjust to what he had at quarterback and on defense. After the first half of the first game, it should have been clear that he didnt have the defense of 2012. And he already knew he had a limited qb. It doesn't take Lombardi to figure out that a strong running game and limiting possessions would be the best way to win games. Instead, he thought it was best smart to let Rees fling it all over the lot and put the defense in bad situations. Of course that led to a middling season of 8-4.
Fast forward to this year. Golson looked great early and seemed like he could run Kelly's offense to a T. Then adversity hit, in the form of a swarm of injuries on the defense and the fact that Golson became a turnover machine. Again, I don't think it takes Lombardi to figure out that the best way to succeed is to keep a young and undermanned defense off the field and limit Golson's chances of turning it over. Kelly had two very good running backs and even a mobile qb in Golson or Zaire. He should have adopted a strong pro style or even RichRodesque running game. Instead he thought the answer was to fling it all over the field, and out score teams. That makes no sense whatsoever.
Those are just two examples of his inability to adjust, but it is problematic with just who he is as a coach. I honestly think he is an above average college football coach (just look around, there are lots of very bad coaches). I also believe that with everybody coming back next season and a very manageable schedule that there is no excuse for ND not to be a top ten team and compete until the final week for the playoff. I also tend to believe that if Golson or Zaire excels at qb and ND doesn's suffer many injuries, that Kelly can have a bounce back year and lead ND to an 11-1 or even 12-0 season. But that is if EVERYTHING goes according to plan. If something goes wrong, then it's back to 8-4 with the excuse de jour.
Kelly reminds me a lot of Rich Rod. Like Rich Rod, I am not sure that Kelly is a great fit at ND like he was not at UM. However, I definitely think that if Kelly went to Arizona State or UCLA or even Tennessee that he could be pretty darn successful. But he doesn't understand what it takes to succeed at ND.
Any ND coach with a pulse can recruit top 15 classes at ND. But what ND needs because of it's academic standards and the fact that to a large majority of high school kids, it's a boring school in the middle of nowhere Indiana, is a coach that recruits to it's historical strengths, which are OL, TE, QB, and LB. Unfortunately Kelly wants to be like the southern and western teams, which is not recruiting to or building a program to it's strengths.
The best thing for ND would be for Kelly to go to an NFL team this off season and for ND to hire Gruden, Dantonio, Adazzio or possibly Mullen. All of whom I believe understand what ND is about and would coach and build the program to its historical strengths. Any of those four would come in and lead ND to a top ten or even five season in 2015.