Conventional Wisdom
Before I begin, let me say that I spent YEARS thanking the Football Gods that the doggies thought Erk Russell was not right for a HFC gig.
1. ADs are risk-adverse. Their jobs as well as their legacies depend on how well they pick a HFC and to a lesser degree a HBC. For that reason, they don't shoot for the sky; they minimize the standard deviations of the downsides.
2. Jon has a coordinator persona that is ideal for the DC job.
3. This persona is not ideal for the HFC.
4. Jon is smart enough to know this, and maintains he would have a different persona as a HFC. He maintains he not only has a great fastball, but a great circle change and a knee-bending curve.
5. ADs agree that Jon is smart enough to try to be something different from what he's shown over the years.
6.
7. ADs worry that in times of stress the "real" Jon would come out. He would walk into a presser being the Calm Jon, and 20 minutes later most of the reporters in the room would be missing limbs. Think of Kill Bill I in the Japanese nightclub.
8. It is in times of stress that you most need the mature confident self-assured HFC, not when things are fine.
9. You can take a coach like Chan, whip him, beat him, and call him "Edna", and you can count on him maintaining his composure. ADs like that. Jon can't convince him that the same would be true for him.
10. If Jon gets a head gig somewhere and flourishes, the same ADs that would not give him the time of day would be calling intermediaries to "gauge interest" on their next opening. Until then....
11. I dunno what would happen with Jon as a HFC. I suspect he would win a lot of football games, and make some enemies in the press. I'd hire him, but I am not risk-adverse.
12. With that said, I think of the last 5 years at GT with things that have happened outside the HFC's control. You know the litany: 6th string running back due to injuries, shortage of returning functional quarterbacks, a gap in recruiting offensive linemen, Carole Moore's macabre masterpiece, arcane probation, etc. It takes a special human being to guide a school through all that without even having a losing record, much less having the wheels come totally off, and then being carped on by lesser men in the process for not winning ALL the games.
13. I don't think Jon would have pulled it off, but I don't know very many coaches who would have.
Oh, and two things are widely held to be true, and I believe them totally.
a. CJT wants to be a HFC at a good school
b. If CJT has to be just a DC, he enjoys his working relationship with Chan. Having a good boss is important in your work, and it may have made the difference between CJT pursuing a mid-level versus staying here.