I think he had his sights set on greener pastures, maybe one with sheep running around (pun intended) a few years ago. I think he was just waiting for the right opportunity to come his way. His passion seemed to wan after the MSU failed negotiations. Perhaps he felt he accomplished everything he could within the confines of the TCU program - perhaps his personal life played a bigger role in this too - who knows. I think 18 years is a fairly long time to stay in a coaching position, and he did develop our program tremendously during that time. For that he is owed a lot of gratitude.
I'm not terribly upset that he is leaving. No one is bigger than the program, and when a coach or player is unhappy where they are, they will not perform well. Whoever takes the reins I feel will continue what he started, and hopefully propel us further. If its KS, great. He seems to have a great relationship with the players, and recruits.
As far as JS is concerned, I think he behaved a bit cowardly leaving with his tail between his legs after the last loss we had. That was wrong on many levels, and will not be forgotten - especially by the players he left behind, as well as fans/alums who for years had the highest amount of respect for him.
I do not wish success for the Aggies. Sorry. I hope we beat them each and every time we play them.