Yes, that's an interesting subject. When you look at it in totality, quite a career arc. For the first 8 or so years of his head coaching career, there might not have been a more effective coach in college basketball. Not one losing conference record in six years at Tulsa and Georgia - not even a .500 record - including three straight Sweet 16 runs. Then, of course, the national championship at UK. After that, though, there were ups and downs at Kentucky. Still, he was only an overtime away from the Final Four in 2005. Then the arc trends downward for sure after that.
I dislike the Packers, of course, but I watched HBO's / NFL Films' documentary on Vince Lombardi three times, it was so good. What stuck with me from that film was the hard time he had with energy and burnout after a while. He coached in Green Bay only nine years, after which he felt he needed to bow out due to physical and mental exhaustion. Even after 7 or 8 years, he looked 15 or more years older and was clearly showing the strain.
From that and others' experiences, it doesn't take a long time for someone to get played out or burned out. I think Tubby reached that point while at Kentucky and has never really recovered. He did seem to get refreshed right away at Minnesota, and it showed the way he elevated that first team. Do you remember him celebrating Blake's miracle shot against Indiana? Can you imagine him dancing like that again now? I'm not sure I can. Since that time there have been flashes in both him and his teams, but neither has been able to sustain anything for very long.
I do believe the Smith from the '90's is a different Smith than we have here today. I think it takes a high level of energy and determination to coach the way he coached then. He continues to try and do it that way, but the juice is just not there anymore; that gear has been stripped. Too bad, because what I wouldn't give to get that guy and his energy and results now.