Let's look at this in basketball terms since that's the only way some fans can view it..
Cal had Memphis ROLLING. They were selling out an NBA arena every single game. He had them getting 5 star recruits all over the board. He had them in a title game...missed free throws from winning. Memphis offered him more money to stay than UK was offering. He would've gone down as the king and the #1 person ever involved in that program. They were better than UK at the time and he did not need UK.
But UK was the better option. At UK, he had a fanbase dedicated to this team 24/7. He had resources and support like no other. He was the center of the college basketball world.
Clay Travis said when Charlie Strong was leaving UofL, that UofL football was the 4th biggest college program in the state. He ranked UK football and BBALL #1 and #2, and UofL BBALL #3. No matter how well he does, this area is not a college football territory. Its harder to get attention and recruits. Heck, UofL is #3 in the nation right now with the best player, but more people around here are concerned with basketball and Mark Stoops job. Now, UofL is getting plenty of national press. But, when the season ends..the Cards fans are like us and go straight into Basketball mode. Yeah, they'll probably be excited next year because of Lamar...but last year no one really was talking about UofL football. At a power school like LSU, football season never ends.
At LSU, the focus is football all year round. There are recruits in your own backyard that you do not even have to compete for with other schools. At LSU, there are almost 100,000 fans at every single game that dedicate their life to LSU win or lose. When UofL is average..they struggle to get 45,000 in the seats. LSU is a destination job. At LSU, you have donors that will give money and support that cannot be matched by 95% of the schools in the nation.
Now, I do not see Bobby leaving because there's a combination of loyalty to Jurich and the baggage that LSU might not want to bring with them if they can get Jimbo Fisher or Herman anyways. But, you can see why there is a chance he'd give LSU a big look. I mean, he may think that his former assistant Brohm gets to take over for him so he won't feel bad about leaving them in bad hands. Also, people do not often change no matter how hard they try...he is like Larry Brown looking for the next opportunity.
For my money, he'll retire at UofL. But, you never know what could happen.